scsi: aacraid: Avoid setting message byte on completion

The aacraid controller is a RAID controller and the driver will never see
any SCSI messages. Plus it's quite pointless to set the message byte if the
host byte is already set, as the latter takes precedence during error
recovery.  Drop the message byte values for the final result.

Link: https://lore.kernel.org/r/20210113090500.129644-16-hare@suse.de
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>