mtd: rawnand: xway: Stop using nand_release()

This helper is not very useful and very often people get confused:
they use nand_release() instead of nand_cleanup().

Let's stop using nand_release() by calling mtd_device_unregister() and
nand_cleanup() directly.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200519130035.1883-62-miquel.raynal@bootlin.com

drivers/mtd/nand/raw/xway_nand.c

@@ -221,8 +221,12 @@ static int xway_nand_probe(struct platform_device *pdev)
 static int xway_nand_remove(struct platform_device *pdev)
 {
 	struct xway_nand_data *data = platform_get_drvdata(pdev);
+	struct nand_chip *chip = &data->chip;
+	int ret;
 
-	nand_release(&data->chip);
+	ret = mtd_device_unregister(mtd);
+	WARN_ON(ret);
+	nand_cleanup(chip);
 
 	return 0;
 }