dwc_eth_qos: Remove deprecated create_singlethread_workqueue

alloc_workqueue replaces deprecated create_singlethread_workqueue().

A dedicated workqueue has been used since the workitem viz
lp->txtimeout_reinit is involved in reinitialization if a TX timeout
occurs, which is necessary to guarantee forward progress in packet
processing. As a network device can be used during memory reclaim, the
workqueue needs forward progress guarantee under memory pressure.
WQ_MEM_RECLAIM has been set to ensure this.

Since there is only a single work item, explicit concurrency limit is
unnecessary here.
Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/synopsys/dwc_eth_qos.c

@@ -2910,7 +2910,8 @@ static int dwceqos_probe(struct platform_device *pdev)
 		     (unsigned long)ndev);
 	tasklet_disable(&lp->tx_bdreclaim_tasklet);
 
-	lp->txtimeout_handler_wq = create_singlethread_workqueue(DRIVER_NAME);
+	lp->txtimeout_handler_wq = alloc_workqueue(DRIVER_NAME,
+						   WQ_MEM_RECLAIM, 0);
 	INIT_WORK(&lp->txtimeout_reinit, dwceqos_reinit_for_txtimeout);
 
 	platform_set_drvdata(pdev, ndev);