ipv6: Always clone offlink routes.

Do not handle PMTU vs. route lookup creation any differently
wrt. offlink routes, always clone them.

Reported-by: PK <runningdoglackey@yahoo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: davem330

net/ipv6/route.c

@@ -72,8 +72,6 @@
 #define RT6_TRACE(x...) do { ; } while (0)
 #endif
 
-#define CLONE_OFFLINK_ROUTE 0
-
 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort);
 static struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
 static unsigned int	 ip6_default_advmss(const struct dst_entry *dst);
@@ -738,13 +736,8 @@ static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
 
 	if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
 		nrt = rt6_alloc_cow(rt, &fl->fl6_dst, &fl->fl6_src);
-	else {
-#if CLONE_OFFLINK_ROUTE
+	else
 		nrt = rt6_alloc_clone(rt, &fl->fl6_dst);
-#else
-		goto out2;
-#endif
-	}
 
 	dst_release(&rt->dst);
 	rt = nrt ? : net->ipv6.ip6_null_entry;