ipv6: use ip6_flowinfo helper

Signed-off-by: NFlorent Fourcot <florent.fourcot@enst-bretagne.fr>
Reviewed-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/af_inet6.c

@@ -683,8 +683,7 @@ bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb)
 	if (np->rxopt.all) {
 		if ((opt->hop && (np->rxopt.bits.hopopts ||
 				  np->rxopt.bits.ohopopts)) ||
-		    ((IPV6_FLOWINFO_MASK &
-		      *(__be32 *)skb_network_header(skb)) &&
+		    (ip6_flowinfo((struct ipv6hdr *) skb_network_header(skb)) &&
 		     np->rxopt.bits.rxflow) ||
 		    (opt->srcrt && (np->rxopt.bits.srcrt ||
 		     np->rxopt.bits.osrcrt)) ||