If the variable does not exist, just return.
[wine] / dlls / dmloader / dmloader.spec
1 @ stdcall -private DllCanUnloadNow() DMLOADER_DllCanUnloadNow
2 @ stdcall -private DllGetClassObject(long long ptr) DMLOADER_DllGetClassObject
3 @ stdcall -private DllRegisterServer() DMLOADER_DllRegisterServer
4 @ stdcall -private DllUnregisterServer() DMLOADER_DllUnregisterServer