cgroup: Remove populate() documentation

This function was removed by 86f82d5618.

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rob Landley <rob@landley.net>
Cc: Paul Menage <paul@paulmenage.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

Documentation/cgroups/cgroups.txt

@@ -637,16 +637,6 @@ void exit(struct task_struct *task)
 
 Called during task exit.
 
-int populate(struct cgroup *cgrp)
-(cgroup_mutex held by caller)
-
-Called after creation of a cgroup to allow a subsystem to populate
-the cgroup directory with file entries.  The subsystem should make
-calls to cgroup_add_file() with objects of type cftype (see
-include/linux/cgroup.h for details).  Note that although this
-method can return an error code, the error code is currently not
-always handled well.
-
 void post_clone(struct cgroup *cgrp)
 (cgroup_mutex held by caller)