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: 6a643ddb

 ("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>