Merge PR #16363 into master

* refs/remotes/upstream/pull/16363/head:
	mds: fix health checks for multiple filesystems
	mon: fix log message on mds rank stop
	mon: uniform way of referring to MDS daemons
	mds: revise health checks for _FAILED/_DEGRADED
	mon/MDSMonitor: log messages on MDS rank changes

Reviewed-by: Patrick Donnelly <pdonnell@redhat.com>