vlan: enable multiqueue xmits

vlan_dev_hard_start_xmit() & vlan_dev_hwaccel_hard_start_xmit()
select txqueue number 0, instead of using index provided by
skb_get_queue_mapping().

This is not correct after commit 2e59af3d
[vlan: multiqueue vlan device] because
txq->tx_packets  & txq->tx_bytes changes are performed on
a single location, and not the right locking.

Fix is to take the appropriate struct netdev_queue pointer

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>