zsmalloc: add comments for ->inuse to zspage

[akpm@linux-foundation.org: fix grammar]
Signed-off-by: Hui Zhu <zhuhui@xiaomi.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 8b8e0da..4396b82 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -38,6 +38,7 @@
  *	page->lru: links together first pages of various zspages.
  *		Basically forming list of zspages in a fullness group.
  *	page->mapping: class index and fullness group of the zspage
+ *	page->inuse: the number of objects that are used in this zspage
  *
  * Usage of struct page flags:
  *	PG_private: identifies the first component page