Bluetooth: Make __hci_update_background_scan private to hci_request.c

There are no more external users so this API can be made private.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index c0ea310..8aa06cc 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -670,7 +670,7 @@
  *
  * This function requires the caller holds hdev->lock.
  */
-void __hci_update_background_scan(struct hci_request *req)
+static void __hci_update_background_scan(struct hci_request *req)
 {
 	struct hci_dev *hdev = req->hdev;