net: Rename skb_has_frags to skb_has_frag_list

SKBs can be "fragmented" in two ways, via a page array (called
skb_shinfo(skb)->frags[]) and via a list of SKBs (called
skb_shinfo(skb)->frag_list).

Since skb_has_frags() tests the latter, it's name is confusing
since it sounds more like it's testing the former.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index d40b330..1838927 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -637,7 +637,7 @@
 	}
 	mtu -= hlen + sizeof(struct frag_hdr);
 
-	if (skb_has_frags(skb)) {
+	if (skb_has_frag_list(skb)) {
 		int first_len = skb_pagelen(skb);
 		int truesizes = 0;