LU-4778 llog: update catlog when plain log destroyed

When the empty plain log is destroyed while processing
catlog, we should call llog_cat_cleanup() to close the
plain log and update in catlog.

Intel-bug-id: INTL-64

Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Change-Id: I97b1d5cc59e84fdb4888274b48f223a063293647
Reviewed-on: http://review.whamcloud.com/9702
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>