Fixes memory leak of KItemListHeader
Summary:
Fixes memory leak of KItemListHeader
The KItemListHeader passed the listView parent object to the QObject
base class, but that pointer seems to always be nullptr causing the
KItemListHeader to not be memory managed by anything. Instead simple
use the listView as parent pointer.
Test Plan: This leak was found using Address Sanitizer
Reviewers: elvisangelaccio
Reviewed By: elvisangelaccio
Subscribers: elvisangelaccio, kfm-devel
Tags: Dolphin
Differential Revision: https://phabricator.kde.org/D14453