net: hns3: check the return of skb_checksum_help()

commit 9bb5a49 upstream.

Currently skb_checksum_help()'s return is ignored, but it may
return error when it fails to allocate memory when linearizing.

So adds checking for the return of skb_checksum_help().

Fixes: 76ad4f0("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Fixes: 3db084d("net: hns3: Fix for vxlan tx checksum bug")
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/ethernet/hisilicon/hns3/hns3_enet.c

@@ -792,8 +792,6 @@ static bool hns3_tunnel_csum_bug(struct sk_buff *skb)
 	      l4.udp->dest == htons(4790))))
 		return false;
 
-	skb_checksum_help(skb);
-
 	return true;
 }
 
@@ -871,8 +869,7 @@ static int hns3_set_l2l3l4(struct sk_buff *skb, u8 ol4_proto,
 			/* the stack computes the IP header already,
 			 * driver calculate l4 checksum when not TSO.
 			 */
-			skb_checksum_help(skb);
-			return 0;
+			return skb_checksum_help(skb);
 		}
 
 		hns3_set_outer_l2l3l4(skb, ol4_proto, ol_type_vlan_len_msec);
@@ -917,7 +914,7 @@ static int hns3_set_l2l3l4(struct sk_buff *skb, u8 ol4_proto,
 		break;
 	case IPPROTO_UDP:
 		if (hns3_tunnel_csum_bug(skb))
-			break;
+			return skb_checksum_help(skb);
 
 		hns3_set_field(*type_cs_vlan_tso, HNS3_TXD_L4CS_B, 1);
 		hns3_set_field(*type_cs_vlan_tso, HNS3_TXD_L4T_S,
@@ -942,8 +939,7 @@ static int hns3_set_l2l3l4(struct sk_buff *skb, u8 ol4_proto,
 		/* the stack computes the IP header already,
 		 * driver calculate l4 checksum when not TSO.
 		 */
-		skb_checksum_help(skb);
-		return 0;
+		return skb_checksum_help(skb);
 	}
 
 	return 0;