LU-17871 ldlm: FLOCK ownlocks may be not set

LU-17871 ldlm: FLOCK ownlocks may be not set

Conflict checking loop should continue until ownlocks is set.
Ownlocks variable is essential for lock merges.

Change-Id: Ied526581dd7d4f100c95f2fe582d117a87a8a584
Fixes: b07a57027e (LU-15402 ldlm: speedup RD flock enqueue)
HPE-bug-id: LUS-12243
Signed-off-by: Andriy Skulysh <andriy.skulysh@hpe.com>
Reviewed-by: Vitaly Fertman <vitaly.fertman@hpe.com>
Reviewed-by: Alexander Boyko <alexander.boyko@hpe.com>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55184
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Sergey Cheremencev <scherementsev@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>