tcp: Set read_sock and peek_len proto_ops

In inet_stream_ops we set read_sock to tcp_read_sock and peek_len to
tcp_peek_len (which is just a stub function that calls tcp_inq).

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tcp.h

@@ -1848,6 +1848,8 @@ static inline int tcp_inq(struct sock *sk)
 	return answ;
 }
 
+int tcp_peek_len(struct socket *sock);
+
 static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb)
 {
 	u16 segs_in;