"invalid memory address or nil pointer dereference" panic seen in CI job after egressIP related annotation   

Panic seen in below CI job for 4.13
https://qe-private-deck-ci.apps.ci.l2s4.p1.openshiftapps.com/view/gs/qe-private-deck/pr-logs/pull/openshift_release/58059/rehearse-58059-periodic-ci-openshift-openshift-tests-private-release-4.13-arm64-nightly-aws-ipi-f28-longduration-mco-all/1848710115369160704

https://gcsweb-qe-private-deck-ci.apps.ci.l2s4.p1.openshiftapps.com/gcs/qe-private-deck/pr-logs/pull/openshift_release/58059/rehearse-58059-periodic-ci-openshift-openshift-tests-private-release-4.13-arm64-nightly-aws-ipi-f28-longduration-mco-all/1848710115369160704/artifacts/aws-ipi-f28-longduration-mco-all/gather-extra/artifacts/pods/openshift-cloud-network-config-controller_cloud-network-config-controller-585c6b4978-bgpqf_controller_previous.log   I1023 01:17:19.445543       1 node_controller.go:142] Setting annotation: 'cloud.network.openshift.io/egress-ipconfig: [{"interface":"eni-007396547172a8deb","ifaddr":{"ipv4":"10.0.128.0/18"},"capacity":{"ipv4":14,"ipv6":15}}]' on node: ip-10-0-158-175.ec2.internalI1023 01:17:19.480462       1 controller.go:160] Dropping key 'ip-10-0-158-175.ec2.internal' from the node workqueueE1023 01:17:19.501431       1 runtime.go:79] Observed a panic: "invalid memory address or nil pointer dereference" (runtime error: invalid memory address or nil pointer dereference)goroutine 131 [running]:k8s.io/apimachinery/pkg/util/runtime.logPanic({0x1fdd580?, 0x3911c20})	/go/src/github.com/openshift/cloud-network-config-controller/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:75 +0x84k8s.io/apimachinery/pkg/util/runtime.HandleCrash({0x0, 0x0, 0x400011f1d0?})	/go/src/github.com/openshift/cloud-network-config-controller/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:49 +0x80panic({0x1fdd580, 0x3911c20})	/usr/lib/golang/src/runtime/panic.go:884 +0x20cgithub.com/openshift/cloud-network-config-controller/pkg/cloudprovider.(*AWS).getSubnet(0x400037a3c0, 0x4000260000)	/go/src/github.com/openshift/cloud-network-config-controller/pkg/cloudprovider/aws.go:265 +0x240github.com/openshift/cloud-network-config-controller/pkg/cloudprovider.(*AWS).GetNodeEgressIPConfiguration(0x40000f0c98?, 0x27d4fb0?, {0x0, 0x0, 0x0})	/go/src/github.com/openshift/cloud-network-config-controller/pkg/cloudprovider/aws.go:199 +0x16cgithub.com/openshift/cloud-network-config-controller/pkg/controller/node.(*NodeController).SyncHandler(0x4000562bb0, {0x400057cd60, 0x1c})	/go/src/github.com/openshift/cloud-network-config-controller/pkg/controller/node/node_controller.go:129 +0x334github.com/openshift/cloud-network-config-controller/pkg/controller.(*CloudNetworkConfigController).processNextWorkItem.func1(0x4000673c80, {0x1df64a0?, 0x400011f1d0?})	/go/src/github.com/openshift/cloud-network-config-controller/pkg/controller/controller.go:152 +0xd0github.com/openshift/cloud-network-config-controller/pkg/controller.(*CloudNetworkConfigController).processNextWorkItem(0x4000673c80)	/go/src/github.com/openshift/cloud-network-config-controller/pkg/controller/controller.go:162 +0x44github.com/openshift/cloud-network-config-controller/pkg/controller.(*CloudNetworkConfigController).runWorker(0x4000024688?)	/go/src/github.com/openshift/cloud-network-config-controller/pkg/controller/controller.go:113 +0x28k8s.io/apimachinery/pkg/util/wait.BackoffUntil.func1(0x46b0?)	/go/src/github.com/openshift/cloud-network-config-controller/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:157 +0x40k8s.io/apimachinery/pkg/util/wait.BackoffUntil(0x2?, {0x27b3dc0, 0x400014fe90}, 0x1, 0x4000182720)	/go/src/github.com/openshift/cloud-network-config-controller/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:158 +0x90k8s.io/apimachinery/pkg/util/wait.JitterUntil(0x0?, 0x3b9aca00, 0x0, 0x1?, 0x1?)	/go/src/github.com/openshift/cloud-network-config-controller/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:135 +0x80k8s.io/apimachinery/pkg/util/wait.Until(0x0?, 0x0?, 0x0?)	/go/src/github.com/openshift/cloud-network-config-controller/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:92 +0x28created by github.com/openshift/cloud-network-config-controller/pkg/controller.(*CloudNetworkConfigController).Run	/go/src/github.com/openshift/cloud-network-config-controller/pkg/controller/controller.go:99 +0x314panic: runtime error: invalid memory address or nil pointer dereference [recovered]	panic: runtime error: invalid memory address or nil pointer dereference[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x1996790]
goroutine 131 [running]:k8s.io/apimachinery/pkg/util/runtime.HandleCrash({0x0, 0x0, 0x400011f1d0?})	/go/src/github.com/openshift/cloud-network-config-controller/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:56 +0xecpanic({0x1fdd580, 0x3911c20})	/usr/lib/golang/src/runtime/panic.go:884 +0x20cgithub.com/openshift/cloud-network-config-controller/pkg/cloudprovider.(*AWS).getSubnet(0x400037a3c0, 0x4000260000)	/go/src/github.com/openshift/cloud-network-config-controller/pkg/cloudprovider/aws.go:265 +0x240github.com/openshift/cloud-network-config-controller/pkg/cloudprovider.(*AWS).GetNodeEgressIPConfiguration(0x40000f0c98?, 0x27d4fb0?, {0x0, 0x0, 0x0})	/go/src/github.com/openshift/cloud-network-config-controller/pkg/cloudprovider/aws.go:199 +0x16cgithub.com/openshift/cloud-network-config-controller/pkg/controller/node.(*NodeController).SyncHandler(0x4000562bb0, {0x400057cd60, 0x1c})	/go/src/github.com/openshift/cloud-network-config-controller/pkg/controller/node/node_controller.go:129 +0x334github.com/openshift/cloud-network-config-controller/pkg/controller.(*CloudNetworkConfigController).processNextWorkItem.func1(0x4000673c80, {0x1df64a0?, 0x400011f1d0?})	/go/src/github.com/openshift/cloud-network-config-controller/pkg/controller/controller.go:152 +0xd0github.com/openshift/cloud-network-config-controller/pkg/controller.(*CloudNetworkConfigController).processNextWorkItem(0x4000673c80)	/go/src/github.com/openshift/cloud-network-config-controller/pkg/controller/controller.go:162 +0x44github.com/openshift/cloud-network-config-controller/pkg/controller.(*CloudNetworkConfigController).runWorker(0x4000024688?)	/go/src/github.com/openshift/cloud-network-config-controller/pkg/controller/controller.go:113 +0x28k8s.io/apimachinery/pkg/util/wait.BackoffUntil.func1(0x46b0?)	/go/src/github.com/openshift/cloud-network-config-controller/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:157 +0x40k8s.io/apimachinery/pkg/util/wait.BackoffUntil(0x2?, {0x27b3dc0, 0x400014fe90}, 0x1, 0x4000182720)	/go/src/github.com/openshift/cloud-network-config-controller/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:158 +0x90k8s.io/apimachinery/pkg/util/wait.JitterUntil(0x0?, 0x3b9aca00, 0x0, 0x1?, 0x1?)	/go/src/github.com/openshift/cloud-network-config-controller/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:135 +0x80k8s.io/apimachinery/pkg/util/wait.Until(0x0?, 0x0?, 0x0?)	/go/src/github.com/openshift/cloud-network-config-controller/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:92 +0x28created by github.com/openshift/cloud-network-config-controller/pkg/controller.(*CloudNetworkConfigController).Run	/go/src/github.com/openshift/cloud-network-config-controller/pkg/controller/controller.go:99 +0x314

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    There should be no "invalid memory address or nil pointer dereference" panic

    must gather: https://gcsweb-qe-private-deck-ci.apps.ci.l2s4.p1.openshiftapps.com/gcs/qe-private-deck/pr-logs/pull/openshift_release/58059/rehearse-58059-periodic-ci-openshift-openshift-tests-private-release-4.13-arm64-nightly-aws-ipi-f28-longduration-mco-all/1848710115369160704/artifacts/aws-ipi-f28-longduration-mco-all/gather-must-gather/artifacts/