workqueue: remove deprecated WQ_NON_REENTRANT

Tejun Heo has made WQ_NON_REENTRANT useless in the dbf2576e
("workqueue: make all workqueues non-reentrant"). So remove its
usages and definition.

This patch doesn't introduce any behavior changes.

tj: minor description updates.
Signed-off-by: NZhangZhen <zhenzhang.zhang@huawei.com>
Sigend-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NJames Chapman <jchapman@katalix.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/dw_mmc.c

@@ -2607,7 +2607,7 @@ int dw_mci_probe(struct dw_mci *host)
 
 	tasklet_init(&host->tasklet, dw_mci_tasklet_func, (unsigned long)host);
 	host->card_workqueue = alloc_workqueue("dw-mci-card",
-			WQ_MEM_RECLAIM | WQ_NON_REENTRANT, 1);
+			WQ_MEM_RECLAIM, 1);
 	if (!host->card_workqueue) {
 		ret = -ENOMEM;
 		goto err_dmaunmap;

include/linux/workqueue.h

@@ -284,12 +284,6 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; }
  * Documentation/workqueue.txt.
  */
 enum {
-	/*
-	 * All wqs are now non-reentrant making the following flag
-	 * meaningless.  Will be removed.
-	 */
-	WQ_NON_REENTRANT	= 1 << 0, /* DEPRECATED */
-
 	WQ_UNBOUND		= 1 << 1, /* not bound to any cpu */
 	WQ_FREEZABLE		= 1 << 2, /* freeze during suspend */
 	WQ_MEM_RECLAIM		= 1 << 3, /* may be used for memory reclaim */

net/l2tp/l2tp_core.c

@@ -2016,7 +2016,7 @@ static int __init l2tp_init(void)
 	if (rc)
 		goto out;
 
-	l2tp_wq = alloc_workqueue("l2tp", WQ_NON_REENTRANT | WQ_UNBOUND, 0);
+	l2tp_wq = alloc_workqueue("l2tp", WQ_UNBOUND, 0);
 	if (!l2tp_wq) {
 		pr_err("alloc_workqueue failed\n");
 		rc = -ENOMEM;