Bluetooth: Add helper function for clearing the discovery filter

The discovery filter allocates memory for its UUID list. So use
a helper function to free it and reset it to default states.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

include/net/bluetooth/hci_core.h

@@ -509,6 +509,14 @@ static inline void discovery_init(struct hci_dev *hdev)
 	hdev->discovery.rssi = HCI_RSSI_INVALID;
 }
 
+static inline void hci_discovery_filter_clear(struct hci_dev *hdev)
+{
+	hdev->discovery.rssi = HCI_RSSI_INVALID;
+	hdev->discovery.uuid_count = 0;
+	kfree(hdev->discovery.uuids);
+	hdev->discovery.uuids = NULL;
+}
+
 bool hci_discovery_active(struct hci_dev *hdev);
 
 void hci_discovery_set_state(struct hci_dev *hdev, int state);

net/bluetooth/hci_core.c

@@ -2061,10 +2061,7 @@ void hci_discovery_set_state(struct hci_dev *hdev, int state)
 		 * count, it is important to actually free the allocated
 		 * list of UUIDs here.
 		 */
-		hdev->discovery.rssi = HCI_RSSI_INVALID;
-		hdev->discovery.uuid_count = 0;
-		kfree(hdev->discovery.uuids);
-		hdev->discovery.uuids = NULL;
+		hci_discovery_filter_clear(hdev);
 
 		if (old_state != DISCOVERY_STARTING)
 			mgmt_discovering(hdev, 0);