Merge pull request #6198 from XinzeChi/wip-buffer-history-alloc

common: perf counter for bufferlist history total alloc

Reviewed-by: Sage Weil <sage@redhat.com>

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

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

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

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