trivial: fix where cgroup documentation is not correctly referred to

cgroup documentation was moved to Documentation/cgroups/. There are some
places that still refer to Documentation/controllers/,
Documentation/cgroups.txt and Documentation/cpusets.txt. Fix those.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/init/Kconfig b/init/Kconfig
index bcffc0e..99eb419 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -565,7 +565,7 @@
 	select MM_OWNER
 	help
 	  Provides a memory resource controller that manages both anonymous
-	  memory and page cache. (See Documentation/controllers/memory.txt)
+	  memory and page cache. (See Documentation/cgroups/memory.txt)
 
 	  Note that setting this option increases fixed memory overhead
 	  associated with each page of memory in the system. By this,