dinput: Prevent race between destroying the hook window and unloading the dll.

[Alexandre Julliard]

Vitaliy Margolen <wine-patches at kievinfo.com> writes:

>      else ERR("Error creating message window\n");
>  
> +    UnregisterClassW(classW, DINPUT_instance);
>      return 0;

You need to clear the class atom if you unregister the class,
otherwise the next window creation will fail.

-- 
Alexandre Julliard
julliard at winehq.org