scsi: 53c700: Use scsi_cmd_to_rq() instead of scsi_cmnd.request

Prepare for removal of the request pointer by using scsi_cmd_to_rq()
instead. This patch does not change any functionality.

Link: https://lore.kernel.org/r/[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/53c700.c

···
 
 	if ((hostdata->tag_negotiated & (1<<scmd_id(SCp))) &&
 	    SCp->device->simple_tags) {
-		slot->tag = SCp->request->tag;
+		slot->tag = scsi_cmd_to_rq(SCp)->tag;
 		CDEBUG(KERN_DEBUG, SCp, "sending out tag %d, slot %p\n",
 		       slot->tag, slot);
 	} else {