Code convention review and correction after comment on github

https://github.com/chamilo/chamilo-lms/commit/301fb962da7eb87ddb8eff15deee92804228fda1#commitcomment-5686807

https://github.com/chamilo/chamilo-lms/commit/edb349cae55a812a912fa74e525405cce8546677#commitcomment-5682691

https://github.com/chamilo/chamilo-lms/commit/044b39d98f508c71e47d42d5e69738af7a1b98fd#commitcomment-5657332