[SCSI] dc395x: uninitialized variable in device_alloc()

This bug was introduced back in bitkeeper days in 2003.  We use
"dcb->dev_mode" before it has been initialized.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Oliver Neukum <oliver@neukum.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>