When we omit the --manage-cgroups on dump the controllers section
in cgroups image lacks the none-d entries (the name=systemd is the
most typical).

If it happens, that init task lives in non-criu cgset (it can be
so if we do --shell-job dump from another terminal and see criu
and root task living in different user.slice systemd cgroups) then
on restore the move_in_cgroup() would fail to lookup the required
controller.

In order to fix this we should still call the collect_cgroups()
on dump, so that it adds the none-d controllers into the list,
but don't dump the dirs tree itself.

The patch looks ugly, but it just moves the current_controller
evaluation from the middle of the loop upwards (and renames the
char *opts variable not to conflict with global opts).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Tycho Andersen <tycho.andersen@canonical.com>