small typo in comment fixed
The fonts for Irrlicht are load from sudirectory fonts/ in directory specified with the global "irrlicht_default_obj_dir" (that the user can change from default "../data/").
Previously it was hardcoded into "../data/fonts/" and could not be changed, that was potentially a problem if one needed to have a data directory with a path different than ..data/
Improvement to readability and avoids gnu gcc warnings.
Merge branch 'develop' of https://github.com/projectchrono/chrono into develop