net: ipv6: more places need LOOPBACK_IFINDEX for flowi6_iif

To properly match iif in ip rules we have to provide
LOOPBACK_IFINDEX in flowi6_iif, not 0. Some ip6mr_fib_lookup
and fib6_rule_lookup callers need such fix.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 4011617..004fffb 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1273,6 +1273,7 @@
 	struct flowi6 fl6;
 
 	memset(&fl6, 0, sizeof(fl6));
+	fl6.flowi6_iif = LOOPBACK_IFINDEX;
 	fl6.flowi6_oif = oif;
 	fl6.flowi6_mark = mark;
 	fl6.daddr = iph->daddr;
@@ -1294,6 +1295,7 @@
 	struct flowi6 fl6;
 
 	memset(&fl6, 0, sizeof(fl6));
+	fl6.flowi6_iif = LOOPBACK_IFINDEX;
 	fl6.flowi6_oif = oif;
 	fl6.flowi6_mark = mark;
 	fl6.daddr = msg->dest;