net: use dev_change_tx_queue_len() for SIOCSIFTXQLEN

As noticed by Eric, we need to switch to the helper
dev_change_tx_queue_len() for SIOCSIFTXQLEN call path too,
otheriwse still miss dev_qdisc_change_tx_queue_len().

Fixes: 6a643ddb5624 ("net: introduce helper dev_change_tx_queue_len()")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev_ioctl.c

@@ -285,16 +285,9 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)
 		if (ifr->ifr_qlen < 0)
 			return -EINVAL;
 		if (dev->tx_queue_len ^ ifr->ifr_qlen) {
-			unsigned int orig_len = dev->tx_queue_len;
-
-			dev->tx_queue_len = ifr->ifr_qlen;
-			err = call_netdevice_notifiers(
-					NETDEV_CHANGE_TX_QUEUE_LEN, dev);
-			err = notifier_to_errno(err);
-			if (err) {
-				dev->tx_queue_len = orig_len;
+			err = dev_change_tx_queue_len(dev, ifr->ifr_qlen);
+			if (err)
 				return err;
-			}
 		}
 		return 0;