net: add a wrapper sk_entry()

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sock.h

@@ -317,6 +317,11 @@ struct sock {
 /*
  * Hashed lists helper routines
  */
+static inline struct sock *sk_entry(const struct hlist_node *node)
+{
+	return hlist_entry(node, struct sock, sk_node);
+}
+
 static inline struct sock *__sk_head(const struct hlist_head *head)
 {
 	return hlist_entry(head->first, struct sock, sk_node);