Merge PR #22987 into master

* refs/pull/22987/head:
	common,rgw: rename sha1_digest_t
	osd: decrement old chunk's reference count if the chunk has a reference.
	src/test: add a unit test
	osd: using fingerprint OID if fingerprint is set
	osd: add flag interfaces in chunk_info_t
	common/buffer.cc: add sha1 fingerprint
	osd: add fingerprint property
	mon: add a command to set fingerprint algorithm

diff --cc src/common/buffer.cc
Simple merge

diff --cc src/common/options.cc
Simple merge

diff --cc src/include/buffer.h
Simple merge

diff --cc src/mon/OSDMonitor.cc
Simple merge

diff --cc src/osd/PrimaryLogPG.cc
Simple merge

diff --cc src/osd/osd_types.cc
Simple merge

diff --cc src/osd/osd_types.h
Simple merge

diff --cc src/rgw/rgw_common.h
Simple merge