net: Create and use new helper xfrm_dst_child().
Only IPSEC routes have a non-NULL dst->child pointer. And IPSEC
routes are identified by a non-NULL dst->xfrm pointer.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index e6265e2..7d885a4 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -62,7 +62,7 @@ static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
- top_iph->ttl = ip4_dst_hoplimit(dst->child);
+ top_iph->ttl = ip4_dst_hoplimit(xfrm_dst_child(dst));
top_iph->saddr = x->props.saddr.a4;
top_iph->daddr = x->id.daddr.a4;