slip: sl_alloc(): remove unused parameter "dev_t line"

The first and only parameter of sl_alloc() is unused, so remove it.

Fixes: 5342b77c slip: ("Clean up create and destroy")
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/slip/slip.c

@@ -731,7 +731,7 @@ static void sl_sync(void)
 
 
 /* Find a free SLIP channel, and link in this `tty' line. */
-static struct slip *sl_alloc(dev_t line)
+static struct slip *sl_alloc(void)
 {
 	int i;
 	char name[IFNAMSIZ];
@@ -809,7 +809,7 @@ static int slip_open(struct tty_struct *tty)
 
 	/* OK.  Find a free SLIP channel to use. */
 	err = -ENFILE;
-	sl = sl_alloc(tty_devnum(tty));
+	sl = sl_alloc();
 	if (sl == NULL)
 		goto err_exit;