LU-6705 lod: re-order lodsub recovery cleanup

LU-6705 lod: re-order lodsub recovery cleanup

Before MDT stop recovery thread, it should disconnect
the OSP and stop the sub_recovery thread, otherwise
the recovery thread will be blocked by sub_recovery
thread.

The the right steps to stop the MDT recovery thread is
(see mdt_device_fini())

1. Do stack pre_cleanup (by LCFG_PRE_CLEANUP), to disconnect
OSP and stop sub_recovery thread (used for collecting update
records).
2. Stop the recovery thread.
3. Cleanup the update llog ctxt in mdt_stack_fini()
(by LCFG_CLEANUP).

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: I4e938cb87ab02d388bce16bd15d181fd7fcc783b
Reviewed-on: http://review.whamcloud.com/15210
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>