scsi: aacraid: fix leak of data from stack back to userspace

The fields sense_data_size and sense_data are unitialized garbage from
the stack and are being copied back to userspace.  Fix this leak of
stack information by ensuring they are zero'd.

Detected by CoverityScan, CID#1435473 ("Uninitialized scalar variable")

Fixes: 423400e6 ("scsi: aacraid: Include HBA direct interface")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Dave Carroll <david.carroll@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>