fs/buffer do not support large folios as there are many assumptions on the
folio size to be the host page size.  This conversion is one step towards
removing that assumption.  Also this conversion will reduce calls to
compound_head() if folio_create_buffers() calls
folio_create_empty_buffers().

Link: https://lkml.kernel.org/r/20230417123618.22094-5-p.raghav@samsung.comSigned-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>