can: slcan: use netdev helpers to print out messages

Replace printk() calls with corresponding netdev helpers.

Link: https://lore.kernel.org/all/20220628163137.413025-3-dario.binacchi@amarulasolutions.com
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Tested-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/slcan.c

@@ -365,7 +365,7 @@ static netdev_tx_t slc_xmit(struct sk_buff *skb, struct net_device *dev)
 	spin_lock(&sl->lock);
 	if (!netif_running(dev))  {
 		spin_unlock(&sl->lock);
-		printk(KERN_WARNING "%s: xmit: iface is down\n", dev->name);
+		netdev_warn(dev, "xmit: iface is down\n");
 		goto out;
 	}
 	if (sl->tty == NULL) {
@@ -776,8 +776,7 @@ static void __exit slcan_exit(void)
 
 		sl = netdev_priv(dev);
 		if (sl->tty) {
-			printk(KERN_ERR "%s: tty discipline still running\n",
-			       dev->name);
+			netdev_err(dev, "tty discipline still running\n");
 		}
 
 		unregister_netdev(dev);