LU-13991 ldlm: speedup flock reprocess

LU-13991 ldlm: speedup flock reprocess

We can check for deadlock only for first
conflicting lock, the rest deadlock checks
will be performed after cancelation of
first conflicting lock.

Lustre-change: https://review.whamcloud.com/40048
Lustre-commit: dadec10251090ba88c1b39517943e6603ba6d682

Change-Id: I18359db405ab021a4f32ac833de203254097142d
HPE-bug-id: LUS-8509
Signed-off-by: Andriy Skulysh <c17819@cray.com>
Reviewed-on: https://review.whamcloud.com/48320
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>