iio: adc: viperboard: Drop platform_set_drvdata call

Drop call to platform_set_drvdata as driver data is not used anywhere in the
driver

Signed-off-by: Johannes Thumshirn <morbidrsa@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/viperboard_adc.c

@@ -139,8 +139,6 @@ static int vprbrd_adc_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	platform_set_drvdata(pdev, indio_dev);
-
 	return 0;
 }