scsi: hpsa: send ioaccel requests with 0 length down raid path

- Block I/O requests with 0 length transfers which go down the ioaccel
  path. This causes lockup issues down in the basecode.
- These issues have been fixed, but there are customers who are
  experiencing the issues when running older firmware.

Reviewed-by: Scott Benesh <scott.benesh@microsemi.com>
Reviewed-by: Scott Teel <scott.teel@microsemi.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microsemi.com>
Signed-off-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>