None of the callers of find_get_pages_contig() want tail pages.  They all
use order-0 pages today, but if they were converted, they'd want folios.
So just remove the call to find_subpage() instead of replacing it with
folio_page().
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>