amd8111e: Fix rx return code

The amd8111e rx poll routine currently mishandles the case when we
process exactly the number of packets specified in the budget.

This patch is basically as suggested by David Miller.
Signed-off-by: NChris Friesen <cfriesen@nortel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/amd8111e.c

@@ -833,12 +833,14 @@ static int amd8111e_rx_poll(struct napi_struct *napi, int budget)
 
 	} while(intr0 & RINT0);
 
-	/* Receive descriptor is empty now */
-	spin_lock_irqsave(&lp->lock, flags);
-	__netif_rx_complete(dev, napi);
-	writel(VAL0|RINTEN0, mmio + INTEN0);
-	writel(VAL2 | RDMD0, mmio + CMD0);
-	spin_unlock_irqrestore(&lp->lock, flags);
+	if (rx_pkt_limit > 0) {
+		/* Receive descriptor is empty now */
+		spin_lock_irqsave(&lp->lock, flags);
+		__netif_rx_complete(dev, napi);
+		writel(VAL0|RINTEN0, mmio + INTEN0);
+		writel(VAL2 | RDMD0, mmio + CMD0);
+		spin_unlock_irqrestore(&lp->lock, flags);
+	}
 
 rx_not_empty:
 	return num_rx_pkt;