QEMU accidentally exposed the id of -drive (or same value as disk
serial, if provided) in one of the identifiers visible from the guest.
To avoid regression in case when -blockdev will be used we need to
always specify it ourselves.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Upcoming addition of a new field will need to make sure that SCSI disk
serial is tested as well. Add a case to one of the existing tests.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>