drivers: net: generalize napi_complete_done()

napi_complete_done() allows to opt-in for gro_flush_timeout,
added back in linux-3.19, commit 3b47d30396
("net: gro: add a per device gro flush timer")

This allows for more efficient GRO aggregation without
sacrifying latencies.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/calxeda/xgmac.c

@@ -1247,7 +1247,7 @@ static int xgmac_poll(struct napi_struct *napi, int budget)
 	work_done = xgmac_rx(priv, budget);
 
 	if (work_done < budget) {
-		napi_complete(napi);
+		napi_complete_done(napi, work_done);
 		__raw_writel(DMA_INTR_DEFAULT_MASK, priv->base + XGMAC_DMA_INTR_ENA);
 	}
 	return work_done;