Remove page->index access from ceph.
* patches from https://lore.kernel.org/r/
20250217185119.430193-1-willy@infradead.org:
fs: Remove page_mkwrite_check_truncate()
ceph: Pass a folio to ceph_allocate_page_array()
ceph: Convert ceph_move_dirty_page_in_page_array() to move_dirty_folio_in_page_array()
ceph: Remove uses of page from ceph_process_folio_batch()
ceph: Convert ceph_check_page_before_write() to use a folio
ceph: Convert writepage_nounlock() to write_folio_nounlock()
ceph: Convert ceph_readdir_cache_control to store a folio
ceph: Convert ceph_find_incompatible() to take a folio
ceph: Use a folio in ceph_page_mkwrite()
ceph: Remove ceph_writepage()
Link: https://lore.kernel.org/r/20250217185119.430193-1-willy@infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>