ServiceJob::setResult already does a emitResult.
Discovered with the assert created in https://phabricator.kde.org/D9862
I did a objdump -d to be sure:
setError is from KJob and it only sets a member value (d->error = errorCode;)
setErrorText is from KJob also and it only sets a member value (d->errorText = errorText;)
The same as the other two.