scsi: aha152x: Stop using struct scsi_pointer

Remove aha152x_cmd_priv.scsi_pointer by moving the necessary members into
aha152x_cmd_priv proper.

Tested with an Adaptec SlimSCSI APA-1460A card.

Link: https://lore.kernel.org/r/bdc1264b6dd331150bffb737958cab8c9c068fa1.1648070977.git.fthain@linux-m68k.org


Cc: Christoph Hellwig <hch@infradead.org>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>