Bluetooth: hci_sync: Fix missing static warnings

This fixes the following warnings:

>> net/bluetooth/hci_sync.c:1333:5: warning: no previous prototype for
'hci_scan_disable_sync' [-Wmissing-prototypes]
    1333 | int hci_scan_disable_sync(struct hci_dev *hdev, bool rpa_le_conn)
         |     ^~~~~~~~~~~~~~~~~~~~~
>> net/bluetooth/hci_sync.c:1762:5: warning: no previous prototype for
'hci_passive_scan_sync' [-Wmissing-prototypes]
    1762 | int hci_passive_scan_sync(struct hci_dev *hdev)
         |     ^~~~~~~~~~~~~~~~~~~~~

Fixes: e8907f76 ("Bluetooth: hci_sync: Make use of hci_cmd_sync_queue set 3")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_sync.c

@@ -1397,7 +1397,7 @@ static int hci_le_set_addr_resolution_enable_sync(struct hci_dev *hdev, u8 val)
 				     sizeof(val), &val, HCI_CMD_TIMEOUT);
 }
 
-int hci_scan_disable_sync(struct hci_dev *hdev)
+static int hci_scan_disable_sync(struct hci_dev *hdev)
 {
 	int err;
 
@@ -1968,7 +1968,7 @@ static int hci_start_scan_sync(struct hci_dev *hdev, u8 type, u16 interval,
 	return hci_le_set_scan_enable_sync(hdev, LE_SCAN_ENABLE, filter_dup);
 }
 
-int hci_passive_scan_sync(struct hci_dev *hdev)
+static int hci_passive_scan_sync(struct hci_dev *hdev)
 {
 	u8 own_addr_type;
 	u8 filter_policy;