hugetlb: use sizeof() to get the array size

It's better to use sizeof() to get the array size instead of manual
calculation. Minor readability improvement.

Link: https://lkml.kernel.org/r/20220901120030.63318-5-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/hugetlb.c

@@ -4149,11 +4149,11 @@ static void __init hugepages_clear_pages_in_node(void)
 	if (!hugetlb_max_hstate) {
 		default_hstate_max_huge_pages = 0;
 		memset(default_hugepages_in_node, 0,
-			MAX_NUMNODES * sizeof(unsigned int));
+			sizeof(default_hugepages_in_node));
 	} else {
 		parsed_hstate->max_huge_pages = 0;
 		memset(parsed_hstate->max_huge_pages_node, 0,
-			MAX_NUMNODES * sizeof(unsigned int));
+			sizeof(parsed_hstate->max_huge_pages_node));
 	}
 }