Avoid a double emitResult()
Summary:
ServiceJob::setResult already does a emitResult.
Discovered with the assert created in https://phabricator.kde.org/D9862
Reviewers: Frameworks, Plasma, broulik
Reviewed By: Plasma, broulik
Subscribers: broulik, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D10629