Unnecessary bootrom checking when restoring or starting a migrated VM

[Michael-B8]

Whenever a new bhyve VM is started as a migration destination or restored from checkpoint files (without bhyveload-ing or having a bootrom set), it fails the first time, requiring two runs of the command.

# bhyve -c 1 -m 512M -S -H -A -P -s 0:0,hostbridge -s 1:0,lpc -s 4:0,virtio-blk,guest.img -l com1,stdio -R 127.0.0.1 guest_vm_dest
virtual machine cannot be booted
# bhyve -c 1 -m 512M -S -H -A -P -s 0:0,hostbridge -s 1:0,lpc -s 4:0,virtio-blk,guest.img -l com1,stdio -R 127.0.0.1 guest_vm_dest
pci_pause: no such name: virtio-net
...

This is because of the bootrom and vm creation checks in the do_open() function in bhyverun.c.
Is this necessary considering the memory is either migrated or restored to a running state?