Bluetooth: Add chan->ops->set_shutdown()

We need to remove all direct access of struct sock from L2CAP core.
This change is pretty simple and just add a new L2CAP channel callback to
do the work in the L2CAP socket side.

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index ffa78d3..301f25b 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -1136,6 +1136,15 @@
 	sk->sk_state_change(sk);
 }
 
+static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan)
+{
+	struct sock *sk = chan->data;
+
+	lock_sock(sk);
+	sk->sk_shutdown = SHUTDOWN_MASK;
+	release_sock(sk);
+}
+
 static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan)
 {
 	struct sock *sk = chan->data;
@@ -1153,6 +1162,7 @@
 	.ready		= l2cap_sock_ready_cb,
 	.defer		= l2cap_sock_defer_cb,
 	.resume		= l2cap_sock_resume_cb,
+	.set_shutdown	= l2cap_sock_set_shutdown_cb,
 	.get_sndtimeo	= l2cap_sock_get_sndtimeo_cb,
 	.alloc_skb	= l2cap_sock_alloc_skb_cb,
 };