r8152: re-schedule napi for tx

Re-schedule napi after napi_complete() for tx, if it is necessay.

In r8152_poll(), if the tx is completed after tx_bottom() and before
napi_complete(), the scheduling of napi would be lost. Then, no
one handles the next tx until the next napi_schedule() is called.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/r8152.c

@@ -1936,6 +1936,9 @@ static int r8152_poll(struct napi_struct *napi, int budget)
 		napi_complete(napi);
 		if (!list_empty(&tp->rx_done))
 			napi_schedule(napi);
+		else if (!skb_queue_empty(&tp->tx_queue) &&
+			 !list_empty(&tp->tx_free))
+			napi_schedule(napi);
 	}
 
 	return work_done;