LU-4920 quota: always clear lqe_lockh on lock cancel

LU-4920 quota: always clear lqe_lockh on lock cancel

In the qsd_id_blocking_ast(), lqe_lockh should always be cleared,
otherwise, quota code will mistakenly assume the id lock is still
valid.

Lustre-change: http://review.whamcloud.com/9965/
Lustre-commit: 73ef5dcd8bcf32e4127e0011357b8bc39472cdba

Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Signed-off-by: Li Xi <lixi@ddn.com>
Change-Id: I653e263176a5415ec32324479fed86d948958ef0
Reviewed-on: http://review.whamcloud.com/11278
Tested-by: Jenkins
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>