Savedata doesn't always resched, add some errcodes.

Core/Dialog/PSPSaveDialog.cpp

@@ -379,7 +379,7 @@ int PSPSaveDialog::Update()
 
 	if (status != SCE_UTILITY_STATUS_RUNNING)
 	{
-		return 0;
+		return SCE_ERROR_UTILITY_INVALID_STATUS;
 	}
 
 	if (!param.GetPspParam()) {
@@ -798,6 +798,9 @@ int PSPSaveDialog::Update()
 
 int PSPSaveDialog::Shutdown()
 {
+	if (status != SCE_UTILITY_STATUS_FINISHED)
+		return SCE_ERROR_UTILITY_INVALID_STATUS;
+
 	PSPDialog::Shutdown();
 	param.SetPspParam(0);
 

Core/HLE/sceUtility.cpp

@@ -124,7 +124,10 @@ int sceUtilitySavedataUpdate(int animSpeed)
 	}
 
 	DEBUG_LOG(HLE,"sceUtilitySavedataUpdate(%d)", animSpeed);
-	return hleDelayResult(saveDialog.Update(), "savedata update", 300);
+	int result = saveDialog.Update();
+	if (result >= 0)
+		return hleDelayResult(result, "savedata update", 300);
+	return result;
 }
 
 #define PSP_AV_MODULE_AVCODEC		0