Introduce QuorumOpType, and make QUORUM_REPORT_BAD compatible
with it.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Signed-off-by: NChanglong Xie <xiecl.fnst@cn.fujitsu.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>