Adjust plasma-desktop to the new fallback prefixes
Summary:
Grepped code for repaintNeeded on prefixes and adjusted as appropriately to match
D4827
Test Plan: Booted, looks the same.
Reviewers: Plasma, broulik
Reviewed By: Plasma, broulik
Subscribers: broulik, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D4830