cciss: make device attrs static

No need to export those device attributes.

In fact, without this patch, we can trip over a build error if cciss
is a built-in and another driver also declares and exports attributes
with the same name.

You'll see errors like:

	drivers/scsi/built-in.o: multiple definition of `dev_attr_lunid'
	drivers/block/built-in.o: first defined here

Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Cc: <mike.miller@hp.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>