hns: do not cast return value of napi_gro_receive to null

Basically no drivers care about the return value here, and there's no
__must_check that would make casting to void sensible, so remove it.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns/hns_enet.c

@@ -699,7 +699,7 @@ static void hns_nic_rx_up_pro(struct hns_nic_ring_data *ring_data,
 	struct net_device *ndev = ring_data->napi.dev;
 
 	skb->protocol = eth_type_trans(skb, ndev);
-	(void)napi_gro_receive(&ring_data->napi, skb);
+	napi_gro_receive(&ring_data->napi, skb);
 }
 
 static int hns_desc_unused(struct hnae_ring *ring)