iio: adc: ad4630: Fix possible use of uninitialized variable

Previously, due to return 0 after goto jump, '*val = temp;' could execute
with temp uninitialized if regmap_read() failed in
ad4630_get_avg_frame_len(). Prevent that by returning the actual error code
if regmap_read() fails in ad4630_get_avg_frame_len().

Suggested-by: Jorge Marques <[email protected]>
Fixes: 5bc31c5 ("iio: adc: ad4630: Use oversampling iio attribute for average mode")
Signed-off-by: Marcelo Schmitt <[email protected]>

Author: machschmitt

drivers/iio/adc/ad4630.c

@@ -339,7 +339,7 @@ static int ad4630_get_avg_frame_len(struct iio_dev *dev, unsigned int *avg_len)
 out:
 	iio_device_release_direct_mode(dev);
 
-	return 0;
+	return ret;
 }
 
 static int ad4630_read_raw(struct iio_dev *indio_dev,