Replace comment by just a failure (#6943)
Replace comment by just a failure (#6943)

- Consistent to other checkers (e.g., checkstyle)
- Commenting only works if maintainers create the PR
Siedlerchr/jabref,Siedlerchr/jabref,sauliusg/jabref,sauliusg/jabref,JabRef/jabref,Siedlerchr/jabref,JabRef/jabref,sauliusg/jabref,JabRef/jabref,Siedlerchr/jabref,JabRef/jabref,sauliusg/jabref