staging: iio: ad7780: remove unnecessary stashed voltage value

This patch removes the unnecessary field int_vref_mv in ad7780_state
referring to the device's voltage.

Signed-off-by: Renato Lui Geh <[e-mail]>
Acked-by: Alexandru Ardelean <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/staging/iio/adc/ad7780.c

···
 	struct regulator		*reg;
 	struct gpio_desc		*powerdown_gpio;
 	unsigned int	gain;
-	u16				int_vref_mv;
 
 	struct ad_sigma_delta sd;
 };
···
 {
 	struct ad7780_state *st;
 	struct iio_dev *indio_dev;
-	int ret, voltage_uv = 0;
+	int ret;
 
 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 	if (!indio_dev)
···
 		dev_err(&spi->dev, "Failed to enable specified AVdd supply\n");
 		return ret;
 	}
-	voltage_uv = regulator_get_voltage(st->reg);
 
 	st->chip_info =
 		&ad7780_chip_info_tbl[spi_get_device_id(spi)->driver_data];
-
-	if (voltage_uv)
-		st->int_vref_mv = voltage_uv / 1000;
-	else
-		dev_warn(&spi->dev, "Reference voltage unspecified\n");
 
 	spi_set_drvdata(spi, indio_dev);