vhost-user-test: check ownership during migration Check that backend source and destination do not have simultaneous ownership during migration. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Thibaut Collet <thibaut.collet@6wind.com>