slirp: add in6_dhcp_multicast()

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
diff --git a/slirp/udp6.c b/slirp/udp6.c
index 9fa314b..7c4a6b0 100644
--- a/slirp/udp6.c
+++ b/slirp/udp6.c
@@ -65,7 +65,7 @@
     /* handle DHCPv6 */
     if (ntohs(uh->uh_dport) == DHCPV6_SERVER_PORT &&
         (in6_equal(&ip->ip_dst, &slirp->vhost_addr6) ||
-         in6_equal(&ip->ip_dst, &(struct in6_addr)ALLDHCP_MULTICAST))) {
+         in6_dhcp_multicast(&ip->ip_dst))) {
         m->m_data += iphlen;
         m->m_len -= iphlen;
         dhcpv6_input(&lhost, m);