r8152: use new helper tcp_v6_gso_csum_prep

Use new helper tcp_v6_gso_csum_prep in additional network drivers.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/r8152.c

@@ -1948,29 +1948,6 @@ static void r8152_csum_workaround(struct r8152 *tp, struct sk_buff *skb,
 	}
 }
 
-/* msdn_giant_send_check()
- * According to the document of microsoft, the TCP Pseudo Header excludes the
- * packet length for IPv6 TCP large packets.
- */
-static int msdn_giant_send_check(struct sk_buff *skb)
-{
-	const struct ipv6hdr *ipv6h;
-	struct tcphdr *th;
-	int ret;
-
-	ret = skb_cow_head(skb, 0);
-	if (ret)
-		return ret;
-
-	ipv6h = ipv6_hdr(skb);
-	th = tcp_hdr(skb);
-
-	th->check = 0;
-	th->check = ~tcp_v6_check(0, &ipv6h->saddr, &ipv6h->daddr, 0);
-
-	return ret;
-}
-
 static inline void rtl_tx_vlan_tag(struct tx_desc *desc, struct sk_buff *skb)
 {
 	if (skb_vlan_tag_present(skb)) {
@@ -2016,10 +1993,11 @@ static int r8152_tx_csum(struct r8152 *tp, struct tx_desc *desc,
 			break;
 
 		case htons(ETH_P_IPV6):
-			if (msdn_giant_send_check(skb)) {
+			if (skb_cow_head(skb, 0)) {
 				ret = TX_CSUM_TSO;
 				goto unavailable;
 			}
+			tcp_v6_gso_csum_prep(skb);
 			opts1 |= GTSENDV6;
 			break;