Merge pull request #21608 from cbodley/wip-dpp

dout: DoutPrefixProvider operates directly on stream

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

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

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

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

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