scsi: core: Remove the request member from struct scsi_cmnd

Since all scsi_cmnd.request users are gone, remove the request pointer
from struct scsi_cmnd.

Link: https://lore.kernel.org/r/20210809230355.8186-53-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_error.c

@@ -2377,7 +2377,6 @@ scsi_ioctl_reset(struct scsi_device *dev, int __user *arg)
 
 	scmd = (struct scsi_cmnd *)(rq + 1);
 	scsi_init_command(dev, scmd);
-	scmd->request = rq;
 	scmd->cmnd = scsi_req(rq)->cmd;
 
 	scmd->scsi_done		= scsi_reset_provider_done_command;

drivers/scsi/scsi_lib.c

@@ -1540,7 +1540,6 @@ static blk_status_t scsi_prepare_cmd(struct request *req)
 
 	scsi_init_command(sdev, cmd);
 
-	cmd->request = req;
 	cmd->tag = req->tag;
 	cmd->prot_op = SCSI_PROT_NORMAL;
 	if (blk_rq_bytes(req))

include/scsi/scsi_cmnd.h

@@ -111,9 +111,6 @@ struct scsi_cmnd {
 				   reconnects.   Probably == sector
 				   size */
 
-	struct request *request;	/* The command we are
-				   	   working on */
-
 	unsigned char *sense_buffer;
 				/* obtained by REQUEST SENSE when
 				 * CHECK CONDITION is received on original