cdrom: track if a cdrom_device_info was opened for data

Set a flag when a cdrom_device_info is opened for writing, instead of
trying to figure out this at release time.  This will allow to eventually
remove the mode argument to the ->release block_device_operation as
nothing but the CDROM drivers uses that argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phillip Potter <phil@philpotter.co.uk>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20230608110258.189493-6-hch@lst.de


Signed-off-by: Jens Axboe <axboe@kernel.dk>