mm/memory: fix a typo in comment "attampt"->"attempt"

There is a comment in typo, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200411004043.14686-1-ethp@qq.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory.c

@@ -2467,7 +2467,7 @@ static inline bool cow_user_page(struct page *dst, struct page *src,
 		}
 
 		/*
-		 * The same page can be mapped back since last copy attampt.
+		 * The same page can be mapped back since last copy attempt.
 		 * Try to copy again under PTL.
 		 */
 		if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE)) {