mtd: nand: ams-delta: remove unnecessary platform_set_drvdata()

The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d0631001288a5974afc0b2a5f568bcdecb4d
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/nand/ams-delta.c

@@ -258,7 +258,6 @@ static int ams_delta_init(struct platform_device *pdev)
  out_mtd:
 	gpio_free_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
 out_gpio:
-	platform_set_drvdata(pdev, NULL);
 	gpio_free(AMS_DELTA_GPIO_PIN_NAND_RB);
 	iounmap(io_base);
 out_free: