crypt32: Don't fail if buffer is NULL, just return required size.
[wine] / dlls / dxdiagn / dxdiagn.spec
1 @ stdcall -private DllCanUnloadNow()
2 @ stdcall -private DllGetClassObject(ptr ptr ptr)
3 @ stdcall -private DllRegisterServer()
4 @ stdcall -private DllUnregisterServer()