ole32/tests: Return interface pointer instead of impl pointer from QI.

dlls/ole32/tests/clipboard.c

@@ -96,7 +96,7 @@ static HRESULT WINAPI EnumFormatImpl_QueryInterface(IEnumFORMATETC *iface, REFII
 
     if (IsEqualGUID(riid, &IID_IUnknown) || IsEqualGUID(riid, &IID_IEnumFORMATETC)) {
         IEnumFORMATETC_AddRef(iface);
-        *ppvObj = This;
+        *ppvObj = &This->IEnumFORMATETC_iface;
         return S_OK;
     }
     *ppvObj = NULL;
@@ -201,7 +201,7 @@ static HRESULT WINAPI DataObjectImpl_QueryInterface(IDataObject *iface, REFIID r
 
     if (IsEqualGUID(riid, &IID_IUnknown) || IsEqualGUID(riid, &IID_IDataObject)) {
         IDataObject_AddRef(iface);
-        *ppvObj = This;
+        *ppvObj = &This->IDataObject_iface;
         return S_OK;
     }
     *ppvObj = NULL;