wined3d: Avoid sizeof on structs with variable length arrays.

[Henri Verbeet]

On 13 June 2012 10:41, Michael Stefaniuc <mstefani at redhat.de> wrote:
> -    object = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(*object));
> +    object = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, FIELD_OFFSET(struct wined3d, adapters[1]));

That's not really a VLA, just a somewhat stupid array of size 1.