hugetlb: kill hugetlbfs_pagecache_page()

Fold hugetlbfs_pagecache_page() into its sole caller to remove some
duplicated code. No functional change intended.

Link: https://lkml.kernel.org/r/20220901120030.63318-8-linmiaohe@huawei.com


Signed-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>