ids: Don't forget to setup task state in write_img_inventory

Need to have proper fake-item state to make this code work ok:

get_task_ids
if (item->state != TASK_DEAD) {
	ret = dump_task_kobj_ids(item);
	if (ret)
		goto err_free;

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>