dmusic: Simplify and cleanup IDirectMusicDownload constructor.

dlls/dmusic/dmusic_private.h

@@ -97,10 +97,11 @@ extern HRESULT DMUSIC_CreateDirectMusicCollectionImpl(REFIID riid, void **ppobj,
 
 /* Internal */
 extern HRESULT DMUSIC_CreateDirectMusicBufferImpl(LPDMUS_BUFFERDESC desc, LPVOID* ret_iface);
-extern HRESULT DMUSIC_CreateDirectMusicDownloadImpl (LPCGUID lpcGUID, LPVOID* ppobj, LPUNKNOWN pUnkOuter);
 extern HRESULT DMUSIC_CreateReferenceClockImpl (LPCGUID lpcGUID, LPVOID* ppobj, LPUNKNOWN pUnkOuter);
 extern HRESULT DMUSIC_CreateDirectMusicInstrumentImpl (LPCGUID lpcGUID, LPVOID* ppobj, LPUNKNOWN pUnkOuter);
 
+extern HRESULT download_create(IDirectMusicDownload **ret_iface);
+
 /*****************************************************************************
  * IDirectMusic8Impl implementation structure
  */

dlls/dmusic/download.c

@@ -85,21 +85,16 @@ static const IDirectMusicDownloadVtbl DirectMusicDownload_Vtbl = {
     IDirectMusicDownloadImpl_GetBuffer
 };
 
-/* for ClassFactory */
-HRESULT DMUSIC_CreateDirectMusicDownloadImpl(const GUID *guid, void **ret_iface, IUnknown *unk_outer)
+HRESULT download_create(IDirectMusicDownload **ret_iface)
 {
     IDirectMusicDownloadImpl *download;
 
-    download = malloc(sizeof(*download));
-    if (!download)
-    {
-        *ret_iface = NULL;
-        return E_OUTOFMEMORY;
-    }
-
+    *ret_iface = NULL;
+    if (!(download = calloc(1, sizeof(*download)))) return E_OUTOFMEMORY;
     download->IDirectMusicDownload_iface.lpVtbl = &DirectMusicDownload_Vtbl;
     download->ref = 1;
-    *ret_iface = download;
 
+    TRACE("Created DirectMusicDownload %p\n", download);
+    *ret_iface = &download->IDirectMusicDownload_iface;
     return S_OK;
 }

dlls/dmusic/port.c

@@ -582,7 +582,7 @@ static HRESULT WINAPI synth_port_download_GetBuffer(IDirectMusicPortDownload *if
     if (!IDMDownload)
         return E_POINTER;
 
-    return DMUSIC_CreateDirectMusicDownloadImpl(&IID_IDirectMusicDownload, (LPVOID*)IDMDownload, NULL);
+    return download_create(IDMDownload);
 }
 
 static HRESULT WINAPI synth_port_download_AllocateBuffer(IDirectMusicPortDownload *iface, DWORD size,