[SCSI] 3w-xxxx: Create sense buffer for unsupported commands

Make the driver return appropriate sense data when an unsupported
operation is queued. This will cause the SCSI layer to stop issuing the
offending command.

Reported-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Adam Radford <aradford@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>