This check shouldn't be necessary, since &error_fatal is given as
argument and will exit() on failure. However, this change should
silence coverity CID 1401761 & 1401705.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190605145829.7674-3-marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>