mm/damon/paddr: fix missing folio_sz update in damon_pa_young()

The *folio_sz in damon_pa_young() will be used(as last_folio_sz) by
__damon_pa_check_access(), so it's need to be updated, fix missing branch.

Link: https://lkml.kernel.org/r/20230308083311.120951-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Kefeng Wang

mm/damon/paddr.c

@@ -134,10 +134,8 @@ static bool damon_pa_young(unsigned long paddr, unsigned long *folio_sz)
 	}
 
 	need_lock = !folio_test_anon(folio) || folio_test_ksm(folio);
-	if (need_lock && !folio_trylock(folio)) {
-		folio_put(folio);
-		return false;
-	}
+	if (need_lock && !folio_trylock(folio))
+		goto out;
 
 	rmap_walk(folio, &rwc);