ceph: resubmit requests on pg mapping change (not just primary change)

ceph: resubmit requests on pg mapping change (not just primary change)

OSD requests need to be resubmitted on any pg mapping change, not just when
the pg primary changes.  Resending only when the primary changes results in
occasional 'hung' requests during osd cluster recovery or rebalancing.

Signed-off-by: Sage Weil <sage@newdream.net>