LU-18214 ldlm: change flock deadlock detection

LU-18214 ldlm: change flock deadlock detection

The flock deadlock detection code thought request lock
same as blocking lock is a bug. In fact, this is a case
of cycling chain. So we should treat it as a deadlock
case. Also clean up the reprocess code.

Signed-off-by: Yang Sheng <ys@whamcloud.com>
Change-Id: Icf0df4ac281c2cdb6cc57cb79db137d39ecef9e6
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56319
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Mikhail Pershin <mpershin@whamcloud.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>