As the comment says, we don't need to restore speical cpuset props twice,
and indeed it can cause the restore to fail, e.g.:

(00.092356) Error (cgroup.c:1240): cg: Failed writing 0-3 to cpuset//lxc/centoss/cpuset.cpus
(00.582490)     18: Error (cgroup.c:1009): cg: Can't move 18 into systemd//lxc/centos/system.slice/systemd-journald.service/tasks (-1/-1): No such file or directory
(00.582497)     18: Error (cgroup.c:1124): cg: Can't move into systemd//lxc/centos/system.slice/systemd-journald.service/tasks (-1/-1): No such file or directory
(00.582567)     43: Error (cgroup.c:1009): cg: Can't move 43 into systemd//lxc/centos/system.slice/console-getty.service/tasks (-1/-1): No such file or directory
(00.582573)     43: Error (cgroup.c:1124): cg: Can't move into systemd//lxc/centos/system.slice/console-getty.service/tasks (-1/-1): No such file or directory
(00.582886)      1: Error (cr-restore.c:1306): 18 exited, status=1
(00.594670) Error (cr-restore.c:1308): 7906 killed by signal 9
(00.623099) Error (cr-restore.c:2138): Restoring FAILED.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>