drivers/net: Kill now superfluous ->last_rx stores.

The generic packet receive code takes care of setting
netdev->last_rx when necessary, for the sake of the
bonding ARP monitor.

Drivers need not do it any more.

Some cases had to be skipped over because the drivers
were making use of the ->last_rx value themselves.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c
index 0f805da..b8ba4bb 100644
--- a/drivers/net/sfc/rx.c
+++ b/drivers/net/sfc/rx.c
@@ -752,7 +752,7 @@
 	channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
 
 done:
-	efx->net_dev->last_rx = jiffies;
+	;
 }
 
 void efx_rx_strategy(struct efx_channel *channel)