inetpeer: Move ICMP rate limiting state into inet_peer entries.

Like metrics, the ICMP rate limiting bits are cached state about
a destination.  So move it into the inet_peer entries.

If an inet_peer cannot be bound (the reason is memory allocation
failure or similar), the policy is to allow.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 5f8d242..2600e22 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -479,10 +479,13 @@
 		else
 			target = &hdr->daddr;
 
+		if (!rt->rt6i_peer)
+			rt6_bind_peer(rt, 1);
+
 		/* Limit redirects both by destination (here)
 		   and by source (inside ndisc_send_redirect)
 		 */
-		if (xrlim_allow(dst, 1*HZ))
+		if (inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ))
 			ndisc_send_redirect(skb, n, target);
 	} else {
 		int addrtype = ipv6_addr_type(&hdr->saddr);