mm/page_alloc: fix comment

Add a necessary 'leave'.
Signed-off-by: NYaowei Bai <bywxiaobai@163.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c

@@ -172,7 +172,7 @@ static void __free_pages_ok(struct page *page, unsigned int order);
  *	1G machine -> (16M dma, 784M normal, 224M high)
  *	NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
  *	HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
- *	HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
+ *	HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
  *
  * TBD: should special case ZONE_DMA32 machines here - in those we normally
  * don't need any ZONE_NORMAL reservation