The migration tests used two VMs each with -m 1024 this caused
problems when run in some small, pessimistic test VMs (netbsd).
We can just be meaner with the amount of RAM in the test and use -m 384

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 20170714152820.24034-1-dgilbert@redhat.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>