mm: use PAGE_ALIGNED instead of IS_ALIGNED

<linux/mm.h> already provides the PAGE_ALIGNED macro.  Let's use this
macro instead of IS_ALIGNED and passing PAGE_SIZE directly.

Link: https://lkml.kernel.org/r/20220526140257.1568744-1-bh1scw@gmail.com


Signed-off-by: Fanjun Kong <bh1scw@gmail.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>