ramips: Change ethernet driver to use napi_complete_done.

Backport of mailine linux commit. Speeds up ethernet slightly and reduces latency.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

target/linux/ramips/files-4.9/drivers/net/ethernet/mtk/mtk_eth_soc.c

@@ -1003,7 +1003,7 @@ static int fe_poll(struct napi_struct *napi, int budget)
 			goto poll_again;
 		}
 
-		napi_complete(napi);
+		napi_complete_done(napi, rx_done);
 		fe_int_enable(tx_intr | rx_intr);
 	} else {
 		rx_done = budget;