dcssblk: remove the end of device check in dcssblk_submit_bio

The block layer already checks for this conditions in bio_check_eod
before calling the driver.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>