mm, hwpoison: use __PageMovable() to detect non-lru movable pages

It's more recommended to use __PageMovable() to detect non-lru movable
pages. We can avoid bumping page refcnt via isolate_movable_page() for
the isolated lru pages. Also if pages become PageLRU just after they're
checked but before trying to isolate them, isolate_lru_page() will be
called to do the right work.

[linmiaohe@huawei.com: fixes per Naoya Horiguchi]
  Link: https://lkml.kernel.org/r/1f7ee86e-7d28-0d8c-e0de-b7a5a94519e8@huawei.com
Link: https://lkml.kernel.org/r/20220830123604.25763-3-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memory-failure.c

@@ -2407,23 +2407,25 @@ EXPORT_SYMBOL(unpoison_memory);
 static bool isolate_page(struct page *page, struct list_head *pagelist)
 {
 	bool isolated = false;
-	bool lru = PageLRU(page);
 
 	if (PageHuge(page)) {
 		isolated = !isolate_hugetlb(page, pagelist);
 	} else {
+		bool lru = !__PageMovable(page);
+
 		if (lru)
 			isolated = !isolate_lru_page(page);
 		else
-			isolated = !isolate_movable_page(page, ISOLATE_UNEVICTABLE);
+			isolated = !isolate_movable_page(page,
+							 ISOLATE_UNEVICTABLE);
 
-		if (isolated)
+		if (isolated) {
 			list_add(&page->lru, pagelist);
-	}
-
-	if (isolated && lru)
+			if (lru)
 				inc_node_page_state(page, NR_ISOLATED_ANON +
 						    page_is_file_lru(page));
+		}
+	}
 
 	/*
 	 * If we succeed to isolate the page, we grabbed another refcount on