Stub out IN6_LOOKUP_MULTI() for GETSPI requests, for now.

This has the effect that IPv6 multicast traffic won't trigger
an SPI allocation when IPSEC is in use, however, this obviously
needs to stomp on locks, and IN6_LOOKUP_MULTI() is about to go away.

This definitely needs to be revisited before 8.x is branched as
a release branch.

sys/netipsec/key.c

@@ -3765,13 +3765,16 @@ key_ismyaddr6(sin6)
 {
 	INIT_VNET_INET6(curvnet);
 	struct in6_ifaddr *ia;
+#if 0
 	struct in6_multi *in6m;
+#endif
 
 	for (ia = V_in6_ifaddr; ia; ia = ia->ia_next) {
 		if (key_sockaddrcmp((struct sockaddr *)&sin6,
 		    (struct sockaddr *)&ia->ia_addr, 0) == 0)
 			return 1;
 
+#if 0
 		/*
 		 * XXX Multicast
 		 * XXX why do we care about multlicast here while we don't care
@@ -3782,6 +3785,7 @@ key_ismyaddr6(sin6)
 		IN6_LOOKUP_MULTI(sin6->sin6_addr, ia->ia_ifp, in6m);
 		if (in6m)
 			return 1;
+#endif
 	}
 
 	/* loopback, just for safety */