scsi: hptiop: Stop using the SCSI pointer

Set .cmd_size in the SCSI host template instead of using the SCSI pointer
from struct scsi_cmnd. This patch prepares for removal of the SCSI pointer
from struct scsi_cmnd.

Rename hpt_scsi_pointer into hpt_cmd_priv because that data structure is
not related to struct scsi_pointer.

Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Johannes Thumshirn <[e-mail]>
Reviewed-by: Himanshu Madhani <[e-mail]>
Reviewed-by: Hannes Reinecke <[e-mail]>
Signed-off-by: Bart Van Assche <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/scsi/hptiop.c

···
 	.slave_configure            = hptiop_slave_config,
 	.this_id                    = -1,
 	.change_queue_depth         = hptiop_adjust_disk_queue_depth,
+	.cmd_size		    = sizeof(struct hpt_cmd_priv),
 };
 
 static int hptiop_internal_memalloc_itl(struct hptiop_hba *hba)

drivers/scsi/hptiop.h

···
 	int                   index;
 };
 
-struct hpt_scsi_pointer {
+struct hpt_cmd_priv {
 	int mapped;
 	int sgcnt;
 	dma_addr_t dma_handle;
 };
 
-#define HPT_SCP(scp) ((struct hpt_scsi_pointer *)&(scp)->SCp)
+#define HPT_SCP(scp) ((struct hpt_cmd_priv *)scsi_cmd_priv(scp))
 
 enum hptiop_family {
 	UNKNOWN_BASED_IOP,