orangefs: Remove orangefs_writepage()

orangefs: Remove orangefs_writepage()

If we add a migrate_folio operation, we can remove orangefs_writepage
(as there is already a writepages operation).  filemap_migrate_folio()
will do fine as struct orangefs_write_range does not need to be adjusted
when the folio is migrated.

Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Link: https://lore.kernel.org/r/20250305204734.1475264-5-willy@infradead.org
Tested-by: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>