LU-6896 llog: update log initialization needs to be sync

LU-6896 llog: update log initialization needs to be sync

During initialization, update llog catlist and cat file creation
needs to be synchronized, because the following update records
will be written to these files, if these files are missing during
update recovery, then update recovery will fail.

Because update llog is initialized in a separate thread, it should
set loc_handle until the catlog is written to catlist to make sure
the udpate llog is fully initialized because MDT can handle cross
MDT operation. see lod_obd_get_info() to check the healthy of the
target.

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: Iccd09749bedde46c01ff89b5be4fa6f4327ec9b9
Reviewed-on: http://review.whamcloud.com/15721
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>