Fix Osu files failing to set a combined filename properly for ssc saving

should fix issues people have with using sync on them
basically without this change, sync changes didnt apply and if you tried to do it, it would produce an empty .ssc file in the install directory, completely useless

src/Etterna/Models/NoteLoaders/NotesLoaderOSU.cpp

@@ -409,6 +409,10 @@ OsuLoader::LoadFromDir(const std::string& sPath_, Song& out)
 		out.AddSteps(chart);
 	}
 
+	// the metadata portion saves the filename/path wrong, this corrects it
+	if (!out.m_sSongFileName.empty())
+		out.m_sSongFileName = sPath_ + out.m_sSongFileName;
+
 	// out.Save(false);
 
 	return true;

src/Etterna/Models/Songs/Song.cpp

@@ -1136,6 +1136,7 @@ Song::Save()
 	GetDirListing(m_sSongDir + "*.ksf", arrayOldFileNames);
 	GetDirListing(m_sSongDir + "*.sm", arrayOldFileNames);
 	GetDirListing(m_sSongDir + "*.dwi", arrayOldFileNames);
+	GetDirListing(m_sSongDir + "*.osu", arrayOldFileNames);
 	for (auto& arrayOldFileName : arrayOldFileNames) {
 		const auto sOldPath = m_sSongDir + arrayOldFileName;
 		const auto sNewPath = sOldPath + ".old";
@@ -1182,8 +1183,10 @@ Song::GetStepsToSave(bool bSavingCache, const std::string& path)
 	vector<Steps*> vpStepsToSave;
 	for (auto& s : m_vpSteps) {
 
-		if (!bSavingCache)
-			s->SetFilename(path);
+		if (!bSavingCache) {
+			if (GetExtension(s->GetFilename()) != "osu")
+				s->SetFilename(path);
+		}
 		vpStepsToSave.push_back(s);
 	}
 	for (auto& s : m_UnknownStyleSteps) {