[SCSI] wd33c93: convert to accessors and !use_sg cleanup

 - convert to accessors and !use_sg cleanup
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/wd33c93.c

@@ -407,16 +407,16 @@ wd33c93_queuecommand(struct scsi_cmnd *cmd,
  *  - SCp.phase records this command's SRCID_ER bit setting
  */
 
-	if (cmd->use_sg) {
-		cmd->SCp.buffer = (struct scatterlist *) cmd->request_buffer;
-		cmd->SCp.buffers_residual = cmd->use_sg - 1;
+	if (scsi_bufflen(cmd)) {
+		cmd->SCp.buffer = scsi_sglist(cmd);
+		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
 	} else {
 		cmd->SCp.buffer = NULL;
 		cmd->SCp.buffers_residual = 0;
-		cmd->SCp.ptr = (char *) cmd->request_buffer;
-		cmd->SCp.this_residual = cmd->request_bufflen;
+		cmd->SCp.ptr = NULL;
+		cmd->SCp.this_residual = 0;
 	}
 
 /* WD docs state that at the conclusion of a "LEVEL2" command, the