Fix daemon-util with non-root user models

Commit 4b42c3d6 broke non-root user mode since, while trying to do a
cleanup a move all local variable definitions to the start of the
function; however, the plain_name var is only defined later, so this
actually doesn't work.

Note that enabling set -u doesn't _directly_ work, since we rely on
some variables which are usually undefined (EXTRA_*_ARGS, etc.). It
can be fixed, but in a later patch.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>