udp: make *udp*_queue_rcv_skb() functions static

Since the udp memory accounting refactor, we don't need any more
to export the *udp*_queue_rcv_skb(). Make them static and fix
a couple of sparse warnings:

net/ipv4/udp.c:1615:5: warning: symbol 'udp_queue_rcv_skb' was not
declared. Should it be static?
net/ipv6/udp.c:572:5: warning: symbol 'udpv6_queue_rcv_skb' was not
declared. Should it be static?

Fixes: 850cbaddb52d ("udp: use it's own memory accounting schema")
Fixes: c915fe13cbaa ("udplite: fix NULL pointer dereference")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ea6e4cf..1d6219b 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1612,7 +1612,7 @@ static void udp_v4_rehash(struct sock *sk)
 	udp_lib_rehash(sk, new_hash);
 }
 
-int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
 	int rc;
 
@@ -1657,7 +1657,7 @@ EXPORT_SYMBOL(udp_encap_enable);
  * Note that in the success and error cases, the skb is assumed to
  * have either been requeued or freed.
  */
-int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
 	struct udp_sock *up = udp_sk(sk);
 	int is_udplite = IS_UDPLITE(sk);