scsi: aacraid: Use correct function to get ctrl health

The command thread checks the ctrl health periodically before sending
updates to the controller. The function that it uses is aac_check_health
which does more than get the health status.

Signed-off-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>
Reviewed-by: David Carroll <david.carroll@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>