bridge: use ipv4_is_local_multicast() helper

Cc: Stephen Hemminger <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Signed-off-by: Cong Wang <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/bridge/br_multicast.c

···
 		return -EINVAL;
 
 	if (iph->protocol != IPPROTO_IGMP) {
-		if ((iph->daddr & IGMP_LOCAL_GROUP_MASK) != IGMP_LOCAL_GROUP)
+		if (!ipv4_is_local_multicast(iph->daddr))
 			BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
 		return 0;
 	}