Systemd provides the status of a given user and system session as a
human readable string.
Retrieve this information via RequestSystemState and guard the
retrieve of failed units depending on this request.
The functionality is extended but does not change, which means that
failed units in any granularity are displayed as before.
Update documentation in the meantime.
Signed-off-by: Steffen Kothe <steffen.kothe@skothe.net>
Split-out request of failed units from systemd into a separate member
function.
This increases the readability and extendability, but preserves the
current functionality (non-functional change).
Signed-off-by: Steffen Kothe <steffen.kothe@skothe.net>
Keeping nr_failed as member allows to split-out calculation of overall
failed units into updateData.
Signed-off-by: Steffen Kothe <steffen.kothe@skothe.net>
