dlm: WQ_NON_REENTRANT is meaningless and going away

dbf2576e ("workqueue: make all workqueues non-reentrant") made
WQ_NON_REENTRANT no-op and the flag is going away.  Remove its usages.

This patch doesn't introduce any behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/ast.c

@@ -267,10 +267,7 @@ void dlm_callback_work(struct work_struct *work)
 int dlm_callback_start(struct dlm_ls *ls)
 {
 	ls->ls_callback_wq = alloc_workqueue("dlm_callback",
-					     WQ_UNBOUND |
-					     WQ_MEM_RECLAIM |
-					     WQ_NON_REENTRANT,
-					     0);
+					     WQ_UNBOUND | WQ_MEM_RECLAIM, 0);
 	if (!ls->ls_callback_wq) {
 		log_print("can't start dlm_callback workqueue");
 		return -ENOMEM;