iio:adc:at91-sama5d2: code cleanup

Use var type for sizeof argument instead of the struct name.
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

drivers/iio/adc/at91-sama5d2_adc.c

@@ -353,8 +353,7 @@ static int at91_adc_probe(struct platform_device *pdev)
 	struct resource	*res;
 	int ret;
 
-	indio_dev = devm_iio_device_alloc(&pdev->dev,
-					  sizeof(struct at91_adc_state));
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
 	if (!indio_dev)
 		return -ENOMEM;