mtd: nand: tmio: return error code of nand_scan() on error

The nand_scan() returns an appropriate error value when it fails.
Use it instead of the fixed error code -ENODEV.

Signed-off-by: Masahiro Yamada <[e-mail]>
Reviewed-by: Marek Vasut <[e-mail]>
Signed-off-by: Boris Brezillon <[e-mail]>

drivers/mtd/nand/tmio_nand.c

···
 	nand_chip->waitfunc = tmio_nand_wait;
 
 	/* Scan to find existence of the device */
-	if (nand_scan(mtd, 1)) {
-		retval = -ENODEV;
+	retval = nand_scan(mtd, 1);
+	if (retval)
 		goto err_irq;
-	}
+
 	/* Register the partitions */
 	retval = mtd_device_parse_register(mtd, NULL, NULL,
 					   data ? data->partition : NULL,