This is basically what everything else in the qemu code base does, so we
can do it here, too.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20180509194302.21585-3-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>