[ntuple, NFC] Improve code comment
[ntuple, NFC] Improve code comment

Co-authored-by: Javier Lopez-Gomez <e93e62598cea284a6e63613b3a81ef9d4b8991a5@cern.ch>
olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root