cg: Remove unused cgroup_dir field

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Tycho Andersen <tycho.andersen@canonical.com>

cgroup.c

@@ -318,7 +318,6 @@ static int add_cgroup(const char *fpath, const struct stat *sb, int typeflag)
 
 		INIT_LIST_HEAD(&ncd->children);
 		ncd->n_children = 0;
-		ncd->controller = current_controller;
 		return 0;
 	}
 

include/cgroup.h

@@ -23,8 +23,6 @@ struct cgroup_dir {
 	/* more cgroup_dirs */
 	struct list_head	children;
 	unsigned int		n_children;
-
-	struct cg_controller	*controller;
 };
 
 /* This describes a particular cgroup controller, e.g. blkio or cpuset.