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>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f1a9a0a..60a4388 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1570,6 +1570,12 @@
 }
 EXPORT_SYMBOL(tcp_read_sock);
 
+int tcp_peek_len(struct socket *sock)
+{
+	return tcp_inq(sock->sk);
+}
+EXPORT_SYMBOL(tcp_peek_len);
+
 /*
  *	This routine copies from a sock struct into the user buffer.
  *