hugetlbfs: make hugepage size conversion more readable

The calculation 1U << (h->order + PAGE_SHIFT - 10) is actually equal to
(PAGE_SHIFT << (h->order)) >> 10.  So we can make it more readable by
replace it with huge_page_size(h) >> 10.

Link: https://lkml.kernel.org/r/20210122083141.24548-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/hugetlbfs/inode.c

@@ -1520,8 +1520,8 @@ static struct vfsmount *__init mount_one_hugetlbfs(struct hstate *h)
 		put_fs_context(fc);
 	}
 	if (IS_ERR(mnt))
-		pr_err("Cannot mount internal hugetlbfs for page size %uK",
-		       1U << (h->order + PAGE_SHIFT - 10));
+		pr_err("Cannot mount internal hugetlbfs for page size %luK",
+		       huge_page_size(h) >> 10);
 	return mnt;
 }