Replace remaining fprintf with tfm::format manually

src/sync.cpp

@@ -57,7 +57,7 @@ struct CLockLocation {
 
     std::string ToString() const
     {
-        return tfm::format(
+        return strprintf(
             "%s %s:%s%s (in thread %s)",
             mutexName, sourceFile, itostr(sourceLine), (fTry ? " (TRY)" : ""), m_thread_name);
     }