net: add more debug info in skb_checksum_help()

This is a followup of previous patch.

Dumping the stack trace is a good start, but printing
basic skb information is probably better.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -3266,15 +3266,17 @@ int skb_checksum_help(struct sk_buff *skb)
 
 	offset = skb_checksum_start_offset(skb);
 	ret = -EINVAL;
-	if (WARN_ON_ONCE(offset >= skb_headlen(skb)))
+	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
+		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
 		goto out;
-
+	}
 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
 
 	offset += skb->csum_offset;
-	if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb)))
+	if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) {
+		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
 		goto out;
-
+	}
 	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
 	if (ret)
 		goto out;