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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index c600631..e6e1278 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -490,6 +490,7 @@
 }
 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);