structured logs are borked in BMO

An upstream partial fix to logging means that the BMO log now contains a mixture of structured and unstructured logs, making it impossible to read with the structured log parsing tool (bmo-log-parse) we use for debugging customer issues.
This is fixed upstream by https://github.com/metal3-io/baremetal-operator/pull/1249, which will get picked up automatically in 4.14 but which needs to be backported to 4.13.