[UDP]: Cleanup UDP encapsulation code

This cleanup fell out after adding L2TP support where a new encap_rcv
funcptr was added to struct udp_sock. Have XFRM use the new encap_rcv
funcptr, which allows us to move the XFRM encap code from udp.c into
xfrm4_input.c.

Make xfrm4_rcv_encap() static since it is no longer called externally.

Signed-off-by: James Chapman <jchapman@katalix.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index d3a898b..ae959e9 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1003,7 +1003,7 @@
 				 u8 **prevhdr);
 
 #ifdef CONFIG_XFRM
-extern int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type);
+extern int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb);
 extern int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen);
 extern int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, unsigned short family);
 #else
@@ -1012,12 +1012,13 @@
  	return -ENOPROTOOPT;
 } 
 
-static inline int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
+static inline int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
 {
  	/* should not happen */
  	kfree_skb(skb);
 	return 0;
 }
+
 static inline int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, unsigned short family)
 {
 	return -EINVAL;