Add brackets for operator precedence

Patch by Francis Herne.

Summary: GCC warns about this with -Wparentheses, applying operators in the right order seems like a good idea.

Test Plan: Recompiled, no compiler warning.

Reviewers: mwolff

Reviewed By: mwolff

Subscribers: mwolff, kdevelop-devel

Projects: KDevelop

Differential Revision: https://phabricator.kde.org/D1102