Merge pull request #7267 from liewegas/wip-fiemap

osd: drop fiemap len=0 magic

http://pulpito.ceph.com/sage-2016-01-25_07:39:08-rados-wip-sage-testing2---basic-smithi/

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

diff --cc src/os/bluestore/BlueStore.cc
Simple merge

diff --cc src/os/kstore/KStore.cc
Simple merge

diff --cc src/os/memstore/MemStore.cc
Simple merge