staging/lustre/ptlrpc: flock deadlock detection does not work

Flock deadlocks are checked on the first attempt to grant
the flock only. If we try again to grant it after its
blocking lock is cancelled, we don't check for deadlocks
which also may exist.

Perform deadlock detection during reprocess

Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-1715
Lustre-change: http://review.whamcloud.com/3553
Signed-off-by: Andriy Skulysh <Andriy_Skulysh@xyratex.com>
Reviewed-by: Vitaly Fertman <vitaly_fertman@xyratex.com>
Reviewed-by: Bruce Korb <bruce_korb@xyratex.com>
Reviewed-by: Keith Mannthey <keith.mannthey@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Peng Tao <bergwolf@gmail.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>