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/a2mp.c b/net/bluetooth/a2mp.c
index 1e99210..74c1477 100644
--- a/net/bluetooth/a2mp.c
+++ b/net/bluetooth/a2mp.c
@@ -710,6 +710,7 @@
 	.teardown = l2cap_chan_no_teardown,
 	.ready = l2cap_chan_no_ready,
 	.defer = l2cap_chan_no_defer,
+	.set_shutdown = l2cap_chan_no_set_shutdown,
 	.get_sndtimeo = l2cap_chan_no_get_sndtimeo,
 };