[2/5] WineD3D: Use unload instead of duplicating buffer remove code

[Henri Verbeet]

2009/12/22 Stefan Dösinger <stefan at codeweavers.com>:
> -            HeapFree(GetProcessHeap(), 0, This->conversion_shift);
> +            IWineD3DBuffer_UnLoad(iface);
> +            This->flags &= ~WINED3D_BUFFER_CREATEBO;
UnLoad() doesn't free "conversion_shift".