iommu/amd: Remove create_workqueue

alloc_workqueue replaces deprecated create_workqueue().

A dedicated workqueue has been used since the workitem (viz
&fault->work), is involved in IO page-fault handling.
WQ_MEM_RECLAIM has been set to guarantee forward progress under memory
pressure, which is a requirement here.
Since there are only a fixed number of work items, explicit concurrency
limit is unnecessary.
Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu_v2.c

@@ -961,7 +961,7 @@ static int __init amd_iommu_v2_init(void)
 	spin_lock_init(&state_lock);
 
 	ret = -ENOMEM;
-	iommu_wq = create_workqueue("amd_iommu_v2");
+	iommu_wq = alloc_workqueue("amd_iommu_v2", WQ_MEM_RECLAIM, 0);
 	if (iommu_wq == NULL)
 		goto out;