advansys: Remove ASC_SCSI_REQ_Q

Removed unused structure ASC_SCSI_REQ_Q and update the
comments to 'ADV_SCSI_REQ_Q'.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>