IB/ucma: 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 "close_wq" queues work items &ctx->close_work (maps to
ucma_close_id) and &con_req_eve->close_work (maps to
ucma_close_event_id). 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/ucma.c

@@ -1638,7 +1638,8 @@ static int ucma_open(struct inode *inode, struct file *filp)
 	if (!file)
 		return -ENOMEM;
 
-	file->close_wq = create_singlethread_workqueue("ucma_close_id");
+	file->close_wq = alloc_ordered_workqueue("ucma_close_id",
+						 WQ_MEM_RECLAIM);
 	if (!file->close_wq) {
 		kfree(file);
 		return -ENOMEM;