ide: don't use req->special

Just replace it with a field of the same name in struct ide_req.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index c21d5c5..17b2e37 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -440,7 +440,7 @@ int ide_raw_taskfile(ide_drive_t *drive, struct ide_cmd *cmd, u8 *buf,
 			goto put_req;
 	}
 
-	rq->special = cmd;
+	ide_req(rq)->special = cmd;
 	cmd->rq = rq;
 
 	blk_execute_rq(drive->queue, NULL, rq, 0);