dcssblk: don't set bd_block_size in ->open

bd_block_size contains a value that matches the logic block size when
opening, so the statement is redundant.  Even if it wasn't the dumb
assignment would cause a a mismatch with bd_inode->i_blkbits.
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

drivers/s390/block/dcssblk.c

@@ -832,7 +832,6 @@ dcssblk_open(struct block_device *bdev, fmode_t mode)
 		goto out;
 	}
 	atomic_inc(&dev_info->use_count);
-	bdev->bd_block_size = 4096;
 	rc = 0;
 out:
 	return rc;