can: af_can: can_pernet_exit(): no need to iterate over and cleanup registered CAN devices

The networking core takes care and unregisters every network device in
a namespace before calling the can_pernet_exit() hook. This patch
removes the unneeded cleanup.
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Suggested-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net/can/af_can.c

@@ -866,27 +866,12 @@ static int can_pernet_init(struct net *net)
 
 static void can_pernet_exit(struct net *net)
 {
-	struct net_device *dev;
-
 	if (IS_ENABLED(CONFIG_PROC_FS)) {
 		can_remove_proc(net);
 		if (stats_timer)
 			del_timer_sync(&net->can.stattimer);
 	}
 
-	/* remove created dev_rcv_lists from still registered CAN devices */
-	rcu_read_lock();
-	for_each_netdev_rcu(net, dev) {
-		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
-			struct can_dev_rcv_lists *dev_rcv_lists = dev->ml_priv;
-
-			BUG_ON(dev_rcv_lists->entries);
-			kfree(dev_rcv_lists);
-			dev->ml_priv = NULL;
-		}
-	}
-	rcu_read_unlock();
-
 	kfree(net->can.rx_alldev_list);
 	kfree(net->can.pkg_stats);
 	kfree(net->can.rcv_lists_stats);