sock: use hlist_entry_safe

Use hlist_entry_safe() instead of open-coding it.
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sock.h

@@ -544,8 +544,7 @@ static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
 
 static inline struct sock *sk_next(const struct sock *sk)
 {
-	return sk->sk_node.next ?
-		hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
+	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
 }
 
 static inline struct sock *sk_nulls_next(const struct sock *sk)