osd: make project_pg_history handle concurrent osdmap publish

osd: make project_pg_history handle concurrent osdmap publish

The class's osdmap may be updated while we are in our loop.  Pass it in
explicitly instead.

Fixes: http://tracker.ceph.com/issues/26970
Signed-off-by: Sage Weil <sage@redhat.com>
(cherry picked from commit cfe6ca82ed800e81e286396b5b7783ca299325f0)

Correction to this commit required because of separating it from very large pull request.
Needed to include part of 4bc01379bbf946d2f5963dcca6b071914117ce4a which
changed endmap from const OSDMap& to const OSDMapRef&.