staging: Fix bdops->check_events() misconversion in cyasblkdev_block.c

Commit cafb0bfca1 (staging: Convert to bdops->check_events())
incorrectly set bd->user_disk_0->events while initializing
bd->user_disk_1.  Fix it.

The problem was spotted by Milton's suspect code pattern detector.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>