net: make skb_dst_pop routine static

As xfrm_output_one() is the only caller of skb_dst_pop(), we should
make skb_dst_pop() localized.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/xfrm/xfrm_output.c

@@ -38,6 +38,18 @@ static int xfrm_skb_check_space(struct sk_buff *skb)
 	return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);
 }
 
+/* Children define the path of the packet through the
+ * Linux networking.  Thus, destinations are stackable.
+ */
+
+static struct dst_entry *skb_dst_pop(struct sk_buff *skb)
+{
+	struct dst_entry *child = dst_clone(skb_dst(skb)->child);
+
+	skb_dst_drop(skb);
+	return child;
+}
+
 static int xfrm_output_one(struct sk_buff *skb, int err)
 {
 	struct dst_entry *dst = skb_dst(skb);