IB/multicast: Remove deprecated create_singlethread_workqueue

alloc_ordered_workqueue() with WQ_MEM_RECLAIM set, replaces
deprecated create_singlethread_workqueue(). This is the identity
conversion.

The workqueue "mcast_wq" queues work item &group->work. It has been
identity converted.

WQ_MEM_RECLAIM has been set to ensure forward progress under
memory pressure.

Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/multicast.c

@@ -882,7 +882,7 @@ int mcast_init(void)
 {
 	int ret;
 
-	mcast_wq = create_singlethread_workqueue("ib_mcast");
+	mcast_wq = alloc_ordered_workqueue("ib_mcast", WQ_MEM_RECLAIM);
 	if (!mcast_wq)
 		return -ENOMEM;