scsi: aacraid: Fix ioctl reset hang

Driver would hang when attempting to send reset from the ioctl interface,
since it would wait to retrieve the ioctl mutex at send shutdown.

Set adapter shutdown and unlock mutex before sending down reset request.

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