[IPSEC]: Get metrics for xfrm_dst from top dst

For the metrics other than MTU, we should also be getting it from
the top dst as opposed to the bottom dst.  With this change, the
user is able to manipulate values such as advmss for individual
hosts behind a remote IPsec gateway.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/xfrm4_policy.c

@@ -133,7 +133,7 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
 		dst_prev->lastuse	= jiffies;
 		dst_prev->header_len	= header_len;
 		dst_prev->trailer_len	= trailer_len;
-		memcpy(&dst_prev->metrics, &rt->u.dst.metrics, sizeof(dst_prev->metrics));
+		memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
 
 		/* Copy neighbout for reachability confirmation */
 		dst_prev->neighbour	= neigh_clone(rt->u.dst.neighbour);

net/ipv6/xfrm6_policy.c

@@ -149,7 +149,7 @@ __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
 		dst_prev->lastuse	= jiffies;
 		dst_prev->header_len	= header_len;
 		dst_prev->trailer_len	= trailer_len;
-		memcpy(&dst_prev->metrics, &rt->u.dst.metrics, sizeof(dst_prev->metrics));
+		memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
 
 		/* Copy neighbour for reachability confirmation */
 		dst_prev->neighbour	= neigh_clone(rt->u.dst.neighbour);