Bluetooth: Remove sk member from struct l2cap_chan

There is no access to chan->sk in L2CAP core now. This change marks the
end of the task of splitting L2CAP between Core and Socket, thus sk is now
gone from struct l2cap_chan.

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/l2cap.h

@@ -435,8 +435,6 @@ struct l2cap_seq_list {
 #define L2CAP_SEQ_LIST_TAIL	0x8000
 
 struct l2cap_chan {
-	struct sock *sk;
-
 	struct l2cap_conn	*conn;
 	struct hci_conn		*hs_hcon;
 	struct hci_chan		*hs_hchan;

net/bluetooth/l2cap_sock.c

@@ -1374,8 +1374,6 @@ static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock,
 
 	l2cap_chan_hold(chan);
 
-	chan->sk = sk;
-
 	l2cap_pi(sk)->chan = chan;
 
 	return sk;