[NET]: Make ->poll() breakout consistent in Intel ethernet drivers.

This makes the ->poll() routines of the E100, E1000, E1000E, IXGB, and
IXGBE drivers complete ->poll() consistently.

Now they will all break out when the amount of RX work done is less
than 'budget'.

At a later time, we may want put back code to include the TX work as
well (as at least one other NAPI driver does, but by in large NAPI
drivers do not do this).  But if so, it should be done consistently
across the board to all of these drivers.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Auke Kok <auke-jan.h.kok@intel.com>
diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c
index a8bef52..d2fb88d 100644
--- a/drivers/net/ixgb/ixgb_main.c
+++ b/drivers/net/ixgb/ixgb_main.c
@@ -1787,14 +1787,13 @@
 {
 	struct ixgb_adapter *adapter = container_of(napi, struct ixgb_adapter, napi);
 	struct net_device *netdev = adapter->netdev;
-	int tx_cleaned;
 	int work_done = 0;
 
-	tx_cleaned = ixgb_clean_tx_irq(adapter);
+	ixgb_clean_tx_irq(adapter);
 	ixgb_clean_rx_irq(adapter, &work_done, budget);
 
-	/* if no Tx and not enough Rx work done, exit the polling mode */
-	if((!tx_cleaned && (work_done == 0))) {
+	/* If budget not fully consumed, exit the polling mode */
+	if (work_done < budget) {
 		netif_rx_complete(netdev, napi);
 		ixgb_irq_enable(adapter);
 	}