LU-6304 ldlm: crash on umount in cleanup_resource

LU-6304 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()

Change-Id: I275c0d29737119d084205e604c336a42e489bfe7
Xyratex-bug-id: MRP-2352
Signed-off-by: Andriy Skulysh <andriy.skulysh@seagate.com>
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
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>