netfilter: nf_conntrack_ipv6: fix comment for packets without data

Remove ambiguity of double negation.
Signed-off-by: NFlorent Fourcot <florent.fourcot@enst-bretagne.fr>
Acked-by: NRick Jones <rick.jones2@hp.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c

@@ -81,8 +81,8 @@ static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
 	}
 	protoff = ipv6_skip_exthdr(skb, extoff, &nexthdr, &frag_off);
 	/*
-	 * (protoff == skb->len) mean that the packet doesn't have no data
-	 * except of IPv6 & ext headers. but it's tracked anyway. - YK
+	 * (protoff == skb->len) means the packet has not data, just
+	 * IPv6 and possibly extensions headers, but it is tracked anyway
 	 */
 	if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
 		pr_debug("ip6_conntrack_core: can't find proto in pkt\n");