Bluetooth: Add clarifying comment to bt_sock_wait_state()

The bt_sock_wait_state requires the sk lock to be held (through
lock_sock) so document it clearly in the code.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

net/bluetooth/af_bluetooth.c

@@ -490,6 +490,7 @@ int bt_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 }
 EXPORT_SYMBOL(bt_sock_ioctl);
 
+/* This function expects the sk lock to be held when called */
 int bt_sock_wait_state(struct sock *sk, int state, unsigned long timeo)
 {
 	DECLARE_WAITQUEUE(wait, current);