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.

Change-Id: I18359db405ab021a4f32ac833de203254097142d
HPE-bug-id: LUS-8509
Signed-off-by: Andriy Skulysh <c17819@cray.com>
Reviewed-by: Vitaly Fertman <c17818@cray.com>
Reviewed-by: Alexander Boyko <c17825@cray.com>
Tested-by: Alexander Lezhoev <c17454@cray.com>
Reviewed-on: https://review.whamcloud.com/40048
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Alexander Boyko <alexander.boyko@hpe.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>