Another attempted fix for process loopback mode.

Public issue https://github.com/mackron/miniaudio/issues/484

miniaudio.h

@@ -20816,24 +20816,24 @@ static ma_result ma_context_get_IAudioClient_UWP__wasapi(ma_context* pContext, m
     MA_ASSERT(ppAudioClient != NULL);
 
     if (pDeviceID != NULL) {
-        MA_COPY_MEMORY(&iid, pDeviceID->wasapi, sizeof(iid));
+        iidStr = (LPOLESTR)pDeviceID->wasapi;
     } else {
         if (deviceType == ma_device_type_capture) {
             iid = MA_IID_DEVINTERFACE_AUDIO_CAPTURE;
         } else {
             iid = MA_IID_DEVINTERFACE_AUDIO_RENDER;
         }
-    }
 
-#if defined(__cplusplus)
+    #if defined(__cplusplus)
         hr = StringFromIID(iid, &iidStr);
-#else
+    #else
         hr = StringFromIID(&iid, &iidStr);
-#endif
+    #endif
         if (FAILED(hr)) {
             ma_log_postf(ma_context_get_log(pContext), MA_LOG_LEVEL_ERROR, "[WASAPI] Failed to convert device IID to string for ActivateAudioInterfaceAsync(). Out of memory.\n");
             return ma_result_from_HRESULT(hr);
         }
+    }
 
     result = ma_completion_handler_uwp_init(&completionHandler);
     if (result != MA_SUCCESS) {
@@ -20850,7 +20850,9 @@ static ma_result ma_context_get_IAudioClient_UWP__wasapi(ma_context* pContext, m
         return ma_result_from_HRESULT(hr);
     }
 
+    if (pDeviceID == NULL) {
         ma_CoTaskMemFree(pContext, iidStr);
+    }
 
     /* Wait for the async operation for finish. */
     ma_completion_handler_uwp_wait(&completionHandler);