Bluetooth: btusb: Fix fall-through warnings

Fix fall-through warnings:
drivers/bluetooth/btusb.c: In function ‘btusb_recv_acl_mtk’:
drivers/bluetooth/btusb.c:4033:3: warning:
this statement may fall through [-Wimplicit-fallthrough=]
 4033 |   usb_disable_autosuspend(data->udev);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/bluetooth/btusb.c:4034:2: note: here
 4034 |  case 0x05ff:  /* Firmware debug logging 1 */
      |  ^~~~

Signed-off-by: mark-yw.chen <mark-yw.chen@mediatek.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>