Staging: iio: adis16209: Adjust a switch statement

Adjust a switch block to explicitly match channels and
return -EINVAL as default case which makes the code
semantically more clear.

Signed-off-by: Shreeya Patel <shreeya.patel23498@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
diff --git a/drivers/staging/iio/accel/adis16209.c b/drivers/staging/iio/accel/adis16209.c
index 68a2f2f..8ffde7e 100644
--- a/drivers/staging/iio/accel/adis16209.c
+++ b/drivers/staging/iio/accel/adis16209.c
@@ -155,10 +155,16 @@ static int adis16209_read_raw(struct iio_dev *indio_dev,
 		switch (chan->type) {
 		case IIO_VOLTAGE:
 			*val = 0;
-			if (chan->channel == 0)
+			switch (chan->channel) {
+			case 0:
 				*val2 = 305180; /* 0.30518 mV */
-			else
+				break;
+			case 1:
 				*val2 = 610500; /* 0.6105 mV */
+				break;
+			default:
+				return -EINVAL;
+			}
 			return IIO_VAL_INT_PLUS_MICRO;
 		case IIO_TEMP:
 			*val = -470;