page_io: remove buffer_head include

page_io never uses buffer_heads to do I/O.

Link: https://lkml.kernel.org/r/20221215214402.3522366-7-willy@infradead.org


Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>