Bluetooth: Fix using system-global workqueue when not necessary

There's a per-HCI device workqueue (hdev->workqueue) that should be used
for general per-HCI device work (except hdev->req_workqueue that's for
hci_request() related work). This patch fixes places using the
system-global work queue and makes them use the hdev->workqueue instead.
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>

net/bluetooth/hci_core.c

@@ -1622,8 +1622,8 @@ static int hci_do_le_scan(struct hci_dev *hdev, u8 type, u16 interval,
 	if (err < 0)
 		return err;
 
-	schedule_delayed_work(&hdev->le_scan_disable,
-			      msecs_to_jiffies(timeout));
+	queue_delayed_work(hdev->workqueue, &hdev->le_scan_disable,
+			   msecs_to_jiffies(timeout));
 
 	return 0;
 }

net/bluetooth/mgmt.c

@@ -1361,7 +1361,8 @@ static bool enable_service_cache(struct hci_dev *hdev)
 		return false;
 
 	if (!test_and_set_bit(HCI_SERVICE_CACHE, &hdev->dev_flags)) {
-		schedule_delayed_work(&hdev->service_cache, CACHE_TIMEOUT);
+		queue_delayed_work(hdev->workqueue, &hdev->service_cache,
+				   CACHE_TIMEOUT);
 		return true;
 	}