D4806: [greeter] Send the auth result through the server instead return value

[Martin Gräßlin]

graesslin added a dependent revision: D5029: Use seccomp for implementing a 
sandbox for kscreenlocker_greet.

REPOSITORY
  R133 KScreenLocker

REVISION DETAIL
  https://phabricator.kde.org/D4806

To: graesslin, #plasma
Cc: plasma-devel, progwolff, lesliezhai, ali-mohamed, jensreuterberg, abetts, 
sebas, apol