remove_video_wnd interface
- Definition：
Int _stdcall remove_video_wnd(void* client, HWND hwnd);
- Parameter：
client:[in]，The client object which is form new_client.
hwnd:[in]，The window's handle which will be stoped to show video
- Return：
Return ERROR_OK if success，else refer to the definition of error number
- Explain：
Stop to show the video on the window.