mtip32xx: fix a smatch warning

Reported smatch warning:
drivers/block/mtip32xx/mtip32xx.c:4163 mtip_block_shutdown() warn: variable dereferenced before check 'dd->disk' (see line 4159)

dd->disk->disk_name accessed before the check if dd->disk is NULL. Fixed this
and access of dd->queue/dd->disk->queue.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/mtip32xx/mtip32xx.c

@@ -4053,26 +4053,24 @@ static int mtip_block_remove(struct driver_data *dd)
  */
 static int mtip_block_shutdown(struct driver_data *dd)
 {
-	dev_info(&dd->pdev->dev,
-		"Shutting down %s ...\n", dd->disk->disk_name);
-
 	/* Delete our gendisk structure, and cleanup the blk queue. */
 	if (dd->disk) {
-		if (dd->disk->queue)
+		dev_info(&dd->pdev->dev,
+			"Shutting down %s ...\n", dd->disk->disk_name);
+
+		if (dd->disk->queue) {
 			del_gendisk(dd->disk);
-		else
+			blk_cleanup_queue(dd->queue);
+		} else
 			put_disk(dd->disk);
+		dd->disk  = NULL;
+		dd->queue = NULL;
 	}
 
-
 	spin_lock(&rssd_index_lock);
 	ida_remove(&rssd_index_ida, dd->index);
 	spin_unlock(&rssd_index_lock);
 
-	blk_cleanup_queue(dd->queue);
-	dd->disk  = NULL;
-	dd->queue = NULL;
-
 	mtip_hw_shutdown(dd);
 	return 0;
 }