Description of problem:
Can't boot into OS after converting rhel6 guest to openstack by v2v

Version-Release number of selected component (if applicable):
virt-v2v-2.0.7-4.el9.x86_64
libguestfs-1.48.4-1.el9.x86_64
guestfs-tools-1.48.2-5.el9.x86_64
nbdkit-server-1.30.8-1.el9.x86_64
libnbd-1.12.6-1.el9.x86_64
libvirt-libs-8.5.0-5.el9.x86_64
qemu-img-7.0.0-10.el9.x86_64

How reproducible:
100%

Steps to Reproduce:
1.Convert a rhel6 guest from VMware to openstack by v2v

1. virt-v2v -ic vpx://root@10.73.73.141/data/10.73.75.219/?no_verify=1 -it vddk -io vddk-libdir=/home/vmware-vix-disklib-distrib -io vddk-thumbprint=1F:97:34:5F:B6:C2:BA:66:46:CB:1A:71:76:7D:6B:50:1E:03:00:EA -o openstack -oo server-id=v2v-appliance esx6.7-rhel6.10-x86_64 -ip /home/passwd -v -x |& tee > convert-rhel6.10-guest-to-openstack.log
   █ 100% [****************************************]

2.Launch the volume as instance after v2v finishing conversion, check guest but find guest can't boot info OS, pls refer to screenshot'rhel6.10-cannot-boot-into-os-on-osp16.png'

3.Check xml info of the guest on compute node, found rhel6 guest has no 'model='virtio-transitional' in disk part

1. virsh dumpxml instance-00000071
   <domain type='kvm' id='53'>
   <name>instance-00000071</name>
   <uuid>8d2f5481-966c-4fd5-9b0e-a8f41dc890b1</uuid>
   <metadata>
   <nova:instance xmlns:nova="http://openstack.org/xmlns/libvirt/nova/1.0">
   <nova:package version="20.6.2-2.20210607104828.el8ost.4"/>
   <nova:name>esx6.7-rhel6.10-x86_64</nova:name>
   <nova:creationTime>2022-08-09 13:24:06</nova:creationTime>
   .....
   <os>
   <type arch='x86_64' machine='pc-q35-rhel8.4.0'>hvm</type>
   <boot dev='hd'/>
   <smbios mode='sysinfo'/>
   </os>
   .....
   <devices>
   <emulator>/usr/libexec/qemu-kvm</emulator>
   <disk type='block' device='disk'>
   <driver name='qemu' type='raw' cache='none' io='native'/>
   <source dev='/dev/sdi' index='1'/>
   <backingStore/>
   <target dev='vda' bus='virtio'/>
   <serial>8513a469-affc-4bfc-87f5-01bd8f05a678</serial>
   <alias name='virtio-disk0'/>
   <address type='pci' domain='0x0000' bus='0x03' slot='0x00' function='0x0'/>
   </disk>
   ......

Actual results:
As above description

Expected results:
Can boot into OS after converting rhel6 guest to openstack by v2v

Additional info:
1.Can't reproduce the bug when convert rhel6 guest to local and rhv because these scenarios have been fixed in bug 1942325 - Virt-v2v should add 'model='virtio-transitional' to RHEL <=6 guest virtio devices during conversion if target is rhel9 system