d3dx9_36/tests: Fix sizeof to be more portable (coverity)

[Henri Verbeet]

On 24 October 2012 02:05, André Hentschel <nerv at dawncrow.de> wrote:
>          face_remap = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY,
> -                               tc[i].num_faces*sizeof(face_remap));
> +                               tc[i].num_faces*sizeof(DWORD*));
>
I'm don't know what Coverity actually says about this, but this looks
just as wrong to me. It's probably supposed to be
"sizeof(*face_remap)".