pktcdvd: remove the call to blk_queue_bounce

pktcdvd is a make_request based stacking driver and thus doesn't have any
addressing limits on it's own.  It also doesn't use bio_data() or
page_address(), so it doesn't need a lowmem bounce either.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>