LU-6717 llog: Create update llog synchronously

LU-6717 llog: Create update llog synchronously

Create remote update llog object synchronously, so
it will make sure the llog object exists, before
the cross-MDT operations will write any update llog
records.

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: I690e94e68b8b64dfe94412f58448f3867f61ff3e
Reviewed-on: http://review.whamcloud.com/15278
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>