Bluetooth: Don't let background scanning interfering with discovery

If we have an active discovery going on we shouldn't do any changes to
LE scanning when hci_update_background_scan() is called (a call which
can happen for many different reasons). This patch fixes the issue by
returning from the function if the discovery state is anything else
except DISCOVERY_STOPPED.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_core.c

@@ -5403,6 +5403,10 @@ void hci_update_background_scan(struct hci_dev *hdev)
 	    test_bit(HCI_UNREGISTER, &hdev->dev_flags))
 		return;
 
+	/* If discovery is active don't interfere with it */
+	if (hdev->discovery.state != DISCOVERY_STOPPED)
+		return;
+
 	hci_req_init(&req, hdev);
 
 	if (list_empty(&hdev->pend_le_conns) &&