mm/page_reporting.c: drop stale list head check in page_reporting_cycle

list_for_each_entry_safe() guarantees that we will never stumble over the
list head; "&page->lru != list" will always evaluate to true.  Let's
simplify.

[david@redhat.com: Changelog refinements]
Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Link: http://lkml.kernel.org/r/20200818084448.33969-1-richard.weiyang@linux.alibaba.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_reporting.c

@@ -178,7 +178,7 @@ page_reporting_cycle(struct page_reporting_dev_info *prdev, struct zone *zone,
 		 * the new head of the free list before we release the
 		 * zone lock.
 		 */
-		if (&page->lru != list && !list_is_first(&page->lru, list))
+		if (!list_is_first(&page->lru, list))
 			list_rotate_to_front(&page->lru, list);
 
 		/* release lock before waiting on report processing */