D18664: Baloo engine: treat every non-success code as a failure

[Valeriy Malov]

valeriymalov added a dependency: D18873: add baloo engine debugging category.

REPOSITORY
  R293 Baloo

REVISION DETAIL
  https://phabricator.kde.org/D18664

To: valeriymalov, #baloo, bruns, poboiko
Cc: cullmann, ngraham, bruns, kde-frameworks-devel, #baloo, ashaposhnikov, 
michaelh, astippich, spoorun, abrahams