staging: lustre: ldlm: crash on umount in cleanup_resource

cfs_hash_for_each_relax() assumes that cfs_hash_put_locked()
doesn't release bd lock, but it isn't true for
ldlm_res_hop_put_locked().

Add recfcount on next hnode in cfs_hash_for_each_relax() and
remove ldlm_res_hop_put_locked()

Signed-off-by: Andriy Skulysh <andriy.skulysh@seagate.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6304


Xyratex-bug-id: MRP-2352
Reviewed-by: Vitaly Fertman <vitaly.fertman@seagate.com>
Reviewed-by: Alexander Boyko <alexander.boyko@seagate.com>
Tested-by: Alexander Lezhoev <alexander.lezhoev@seagate.com>
Reviewed-on: http://review.whamcloud.com/13908


Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>