Bluetooth: mgmt: multi adv for get_current_adv_instance()

Replaces the hard coded instance identifier in
get_current_adv_instance() with the actual current instance identifier
so that this method is prepared to work with more than one advertising
instance.
Signed-off-by: Florian Grandel <fgrandel@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/mgmt.c

@@ -841,7 +841,7 @@ static u8 get_current_adv_instance(struct hci_dev *hdev)
 	 */
 	if (hci_dev_test_flag(hdev, HCI_ADVERTISING_INSTANCE) &&
 	    !hci_dev_test_flag(hdev, HCI_ADVERTISING))
-		return 0x01;
+		return hdev->cur_adv_instance;
 
 	return 0x00;
 }