net/ieee802154/6lowpan.c: Remove unecessary semicolon

Found by http://coccinelle.lip6.fr/Signed-off-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ieee802154/6lowpan.c

@@ -1256,7 +1256,7 @@ static int lowpan_device_event(struct notifier_block *unused,
 		}
 
 		unregister_netdevice_many(&del_list);
-	};
+	}
 
 out:
 	return NOTIFY_DONE;