staging: vt6656: [BUG] main_usb.c oops on device_close move flag earlier.

The vt6656 is prone to resetting on the usb bus.

It seems there is a race condition and wpa supplicant is
trying to open the device via iw_handlers before its actually
closed at a stage that the buffers are being removed.

The device is longer considered open when the
buffers are being removed. So move ~DEVICE_FLAGS_OPENED
flag to before freeing the device buffers.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>