filestore: don't initiate sync on _start_sync if there's a journal
filestore: don't initiate sync on _start_sync if there's a journal

Journal will commit immediately anyway.. don't slow the rest
down with a full commit to disk.

ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph