can: slcan: use KBUILD_MODNAME and define pr_fmt to replace hardcoded names

The driver uses the string "slcan" to populate
tty_ldisc_ops::name. KBUILD_MODNAME also evaluates to "slcan". Use
KBUILD_MODNAME to get rid on the hardcoded string names.

Similarly, the pr_info() and pr_err() hardcoded the "slcan"
prefix. Define pr_fmt so that the "slcan" prefix gets automatically
added.

CC: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Link: https://lore.kernel.org/all/20220728070254.267974-2-dario.binacchi@amarulasolutions.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/slcan/slcan-core.c

@@ -35,6 +35,8 @@
  *
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 
@@ -864,7 +866,7 @@ static struct slcan *slc_alloc(void)
 	if (!dev)
 		return NULL;
 
-	snprintf(dev->name, sizeof(dev->name), "slcan%d", i);
+	snprintf(dev->name, sizeof(dev->name), KBUILD_MODNAME "%d", i);
 	dev->netdev_ops = &slc_netdev_ops;
 	dev->ethtool_ops = &slcan_ethtool_ops;
 	dev->base_addr  = i;
@@ -937,7 +939,7 @@ static int slcan_open(struct tty_struct *tty)
 		rtnl_unlock();
 		err = register_candev(sl->dev);
 		if (err) {
-			pr_err("slcan: can't register candev\n");
+			pr_err("can't register candev\n");
 			goto err_free_chan;
 		}
 	} else {
@@ -1028,7 +1030,7 @@ static int slcan_ioctl(struct tty_struct *tty, unsigned int cmd,
 static struct tty_ldisc_ops slc_ldisc = {
 	.owner		= THIS_MODULE,
 	.num		= N_SLCAN,
-	.name		= "slcan",
+	.name		= KBUILD_MODNAME,
 	.open		= slcan_open,
 	.close		= slcan_close,
 	.hangup		= slcan_hangup,
@@ -1044,8 +1046,8 @@ static int __init slcan_init(void)
 	if (maxdev < 4)
 		maxdev = 4; /* Sanity */
 
-	pr_info("slcan: serial line CAN interface driver\n");
-	pr_info("slcan: %d dynamic interface channels.\n", maxdev);
+	pr_info("serial line CAN interface driver\n");
+	pr_info("%d dynamic interface channels.\n", maxdev);
 
 	slcan_devs = kcalloc(maxdev, sizeof(struct net_device *), GFP_KERNEL);
 	if (!slcan_devs)
@@ -1054,7 +1056,7 @@ static int __init slcan_init(void)
 	/* Fill in our line protocol discipline, and register it */
 	status = tty_register_ldisc(&slc_ldisc);
 	if (status)  {
-		pr_err("slcan: can't register line discipline\n");
+		pr_err("can't register line discipline\n");
 		kfree(slcan_devs);
 	}
 	return status;