mm/page_alloc.c: clean up comment

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 86af1a9..1b84950 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5760,7 +5760,7 @@
 			 * value here.
 			 *
 			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
-			 * deltas controls asynch page reclaim, and so should
+			 * deltas control asynch page reclaim, and so should
 			 * not be capped for highmem.
 			 */
 			unsigned long min_pages;