sch_teql: Use net_device internal stats

We can slightly reduce size of teqlN structure, not duplicating stats
structure in teql_master but using stats field from net_device.stats
for tx_errors and from netdev_queue for tx_bytes/tx_packets/tx_dropped
values.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>