LU-3536 lod: cancel update log after all committed

LU-3536 lod: cancel update log after all committed

Cancel the log cookies after all of updates have been
committed to disk.

In DNE2, the distributed operation will write update log in all
of involve MDTs, when these the updates are committed on all of
MDT, these update records will be cancelled. If one of these MDTs
restart during the operation, it will replay the updates based
on these update records.

The distribute operation will be represent as distribute transaction
(top_multiple_thandle), and all of distribute transaction will be
linked into a list, which is attached to lu_target (see
struct target_distribute_txn_data), after distribute thandle is
committed, the commit thread (distribute_txn_commit_thread) will
update the commit batchid, after it is committed, it will then
cancel the update records.

Change-Id: I3023f95515b2c15307479f7f85c3f13926d4bcc9
Signed-off-by: Wang Di <di.wang@intel.com>
Signed-off-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-on: http://review.whamcloud.com/11572
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>