cgls: add --unit to show units

$ systemd-cgls -u systemd-journald.service machine.slice

I opted for a "global" switch, instead of modifying the behaviour of just one
argument. It seem to be a more useful setting, since usually one will want to
query one or more units, and not mix unit names with paths.

Closes #5156.

0 files changed, 0 insertions, 0 deletions