scsi: hpsa: correct simple mode

Correct issue with hpsa_simple_mode module parameter. Driver was
hanging due to incorrect interrupt setup.

Reviewed-by: Justin Lindley <justin.lindley@microsemi.com>
Reviewed-by: Dave Carroll <david.carroll@microsemi.com>
Reviewed-by: Scott Teel <scott.teel@microsemi.com>
Signed-off-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>