scsi: core: Remove struct scsi_pointer from struct scsi_cmnd

Remove struct scsi_pointer from struct scsi_cmnd since the previous patches
removed all users of that member of struct scsi_cmnd. Additionally, reorder
the members of struct scsi_cmnd such that the statement that the field
below can be modified by the SCSI LLD is again correct.

Link: https://lore.kernel.org/r/20220218195117.25689-50-bvanassche@acm.org
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

include/scsi/scsi_cmnd.h

@@ -123,11 +123,15 @@ struct scsi_cmnd {
 				 * command (auto-sense). Length must be
 				 * SCSI_SENSE_BUFFERSIZE bytes. */
 
+	int flags;		/* Command flags */
+	unsigned long state;	/* Command completion state */
+
+	unsigned int extra_len;	/* length of alignment and padding */
+
 	/*
-	 * The following fields can be written to by the host specific code. 
-	 * Everything else should be left alone. 
+	 * The fields below can be modified by the LLD but the fields above
+	 * must not be modified.
 	 */
-	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
 
 	unsigned char *host_scribble;	/* The host adapter is allowed to
 					 * call scsi_malloc and get some memory
@@ -138,10 +142,6 @@ struct scsi_cmnd {
 					 * to be at an address < 16Mb). */
 
 	int result;		/* Status code from lower level driver */
-	int flags;		/* Command flags */
-	unsigned long state;	/* Command completion state */
-
-	unsigned int extra_len;	/* length of alignment and padding */
 };
 
 /* Variant of blk_mq_rq_from_pdu() that verifies the type of its argument. */