8139too: use napi_complete_done()

Use napi_complete_done() instead of __napi_complete() to :

1) Get support of gro_flush_timeout if opt-in
2) Not rearm interrupts for busy-polling users.
3) use standard NAPI API.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/8139too.c

@@ -2135,14 +2135,10 @@ static int rtl8139_poll(struct napi_struct *napi, int budget)
 	if (likely(RTL_R16(IntrStatus) & RxAckBits))
 		work_done += rtl8139_rx(dev, tp, budget);
 
-	if (work_done < budget) {
+	if (work_done < budget && napi_complete_done(napi, work_done)) {
 		unsigned long flags;
-		/*
-		 * Order is important since data can get interrupted
-		 * again when we think we are done.
-		 */
+
 		spin_lock_irqsave(&tp->lock, flags);
-		__napi_complete(napi);
 		RTL_W16_F(IntrMask, rtl8139_intr_mask);
 		spin_unlock_irqrestore(&tp->lock, flags);
 	}