LU-6846 llog: combine cancel rec and destroy

LU-6846 llog: combine cancel rec and destroy

Merge cancel llog record and llog object destroy in
a single transaction. Otherwise it will cause the
race between cancel record and llog object destroy,
especally when deleting remote record, i.e. if delete
record RPC arrives after destroy, then delete record
will not find the object, cause LBUG.

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: I33773eeb859fffa871ce01689c5bf1b4196a6658
Reviewed-on: http://review.whamcloud.com/15730
Tested-by: Jenkins
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>