atl2: add tx bytes statistic

Signed-off-by: Jay Cliburn <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

drivers/net/atlx/atl2.c

···
 		atomic_set(&adapter->txd_read_ptr, (int)txd_read_ptr);
 
 		/* tx statistics: */
-		if (txs->ok)
+		if (txs->ok) {
+			adapter->net_stats.tx_bytes += txs->pkt_size;
 			adapter->net_stats.tx_packets++;
+		}
 		else
 			adapter->net_stats.tx_errors++;