Prepare for adding more flags.  The "_MASK" suffix is unique, kill it.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NHu Tao <hutao@cn.fujitsu.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>