There is currently a case in which proc_attr_base won't get set when asprintf is able to generate the path, but the file doesn't exist, it will exit proc_attr_base_init_once() without proc_attr_base having been set as the fall-through if/else logic will get bypassed when asprintf is successful.

Without this fix, various commands like aa-status will not properly display which processes have an apparmor profile enforced because it proc_attr_base will always be NULL and therefore the proc attr path won't be able to be generated.