[Task Manager] Avoid crash with QStringBuilder

Authored by broulik on Apr 27 2020, 12:11 PM.

Description

[Task Manager] Avoid crash with QStringBuilder

The lambda returns a QStringBuilder which contains dangling references, see also QTBUG-47066

BUG: 420452
FIXED-IN: 5.18.5

Differential Revision: https://phabricator.kde.org/D29224

Details