Documenation: update cgroup's document path

cgroup's document path is changed to "cgroup-v1". update it.

Signed-off-by: seokhoon.yoon <iamyooon@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/scheduler/sched-design-CFS.txt b/Documentation/scheduler/sched-design-CFS.txt
index f14f493..edd861c 100644
--- a/Documentation/scheduler/sched-design-CFS.txt
+++ b/Documentation/scheduler/sched-design-CFS.txt
@@ -215,7 +215,7 @@
 
    These options need CONFIG_CGROUPS to be defined, and let the administrator
    create arbitrary groups of tasks, using the "cgroup" pseudo filesystem.  See
-   Documentation/cgroups/cgroups.txt for more information about this filesystem.
+   Documentation/cgroup-v1/cgroups.txt for more information about this filesystem.
 
 When CONFIG_FAIR_GROUP_SCHED is defined, a "cpu.shares" file is created for each
 group created using the pseudo filesystem.  See example steps below to create