Bluetooth: initialize skb_queue_head at l2cap_chan_create()

syzbot is hitting "INFO: trying to register non-static key." message [1],
for "struct l2cap_chan"->tx_q.lock spinlock is not yet initialized when
l2cap_chan_del() is called due to e.g. timeout.

Since "struct l2cap_chan"->lock mutex is initialized at l2cap_chan_create()
immediately after "struct l2cap_chan" is allocated using kzalloc(), let's
as well initialize "struct l2cap_chan"->{tx_q,srej_q}.lock spinlocks there.

[1] https://syzkaller.appspot.com/bug?extid=fadfba6a911f6bf71842

Reported-and-tested-by: syzbot <syzbot+fadfba6a911f6bf71842@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/l2cap_core.c

@@ -451,6 +451,8 @@ struct l2cap_chan *l2cap_chan_create(void)
 	if (!chan)
 		return NULL;
 
+	skb_queue_head_init(&chan->tx_q);
+	skb_queue_head_init(&chan->srej_q);
 	mutex_init(&chan->lock);
 
 	/* Set default lock nesting level */