Bluetooth: Add L2CAP channel to skb private data

Adding the channel to the skb private data makes possible to us know which
channel the skb we have came from.

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 a159b0e..cba3162 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -1174,6 +1174,8 @@
 	if (!skb)
 		return ERR_PTR(err);
 
+	bt_cb(skb)->chan = chan;
+
 	return skb;
 }