mm: fix cleancache debugfs directory path

Minor fixes for cleancache about wrong debugfs paths
in documentation and code comment.

Signed-off-by: Marcin Jabrzyk <m.jabrzyk@samsung.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/mm/cleancache.c b/mm/cleancache.c
index d0eac43..053bcd8 100644
--- a/mm/cleancache.c
+++ b/mm/cleancache.c
@@ -25,7 +25,7 @@
 static struct cleancache_ops *cleancache_ops __read_mostly;
 
 /*
- * Counters available via /sys/kernel/debug/frontswap (if debugfs is
+ * Counters available via /sys/kernel/debug/cleancache (if debugfs is
  * properly configured.  These are for information only so are not protected
  * against increment races.
  */