Merge PR #23449 into master

Merge PR #23449 into master

* refs/pull/23449/head:
	osd/OSDMap: cleanup: s/tmpmap/nextmap/
	qa/standalone/osd/osd-backfill-stats: fixes
	osd/OSDMap: clean out pg_temp mappings that exceed pool size
	mon/OSDMonitor: clean temps and upmaps in encode_pending, efficiently
	osd/OSDMapMapping: do not crash if acting > pool size

Reviewed-by: David Zafman <dzafman@redhat.com>
Reviewed-by: xie xingguo <xie.xingguo@zte.com.cn>
Reviewed-by: Neha Ojha <nojha@redhat.com>