This patch slightly optimizes the loopback driver's stats update.
Saves two loads, one add and one increment per packet sent.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
 
        lb_stats = &per_cpu(loopback_stats, get_cpu());
        lb_stats->rx_bytes += skb->len;
-       lb_stats->tx_bytes += skb->len;
+       lb_stats->tx_bytes = lb_stats->rx_bytes;
        lb_stats->rx_packets++;
-       lb_stats->tx_packets++;
+       lb_stats->tx_packets = lb_stats->rx_packets;
        put_cpu();
 
        netif_rx(skb);