fix fastcodeml output (redo 7a445d17)

WriteResults.cpp

@@ -61,8 +61,8 @@ void WriteResults::outputResults(void) {
 
       ims = mParamStr[0].find(branch);
       // This output does not work on BG/Q.
-      // out << std::endl<< std::fixed <<"Branch lengths:" << ims->second <<
-      // std::endl;
+      out << std::endl
+          << std::fixed << "Branch lengths:" << ims->second << std::endl;
     }
     out << "  LnL1: ";