block: pass the operation to bio_{map,copy}_kern

block: pass the operation to bio_{map,copy}_kern

That way the bio can be allocated with the right operation already
set and there is no need to pass the separated 'reading' argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250507120451.4000627-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>