Fix minor EBN and GCC issues

Summary:
Fix some minor issues from EBN

http://ebn.kde.org/krazy/reports/kde-4.x/kdeedu/analitza/index.html

and GCC logs

https://build.kde.org/job/Applications/job/analitza/job/kf5-qt5%20SUSEQt5.12/13/warnings30Result/

Test Plan: Compiles.

Reviewers: KDE Edu, apol

Reviewed By: apol

Subscribers: apol, kde-edu

Tags: KDE Edu

Differential Revision: https://phabricator.kde.org/D25787