staging: iio: isl29018: made error handling consistent

Changed the processing of IIO_CHAN_INFO_INT_TIME in isl29018_write_raw()
to unlock the mutex and return at the end of the function if invalid
input is passed in. This makes the error handling code consistent with
the processing of IIO_CHAN_INFO_CALIBSCALE and IIO_CHAN_INFO_SCALE
within the same function.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/light/isl29018.c

@@ -356,13 +356,8 @@ static int isl29018_write_raw(struct iio_dev *indio_dev,
 		}
 		break;
 	case IIO_CHAN_INFO_INT_TIME:
-		if (chan->type == IIO_LIGHT) {
-			if (val) {
-				mutex_unlock(&chip->lock);
-				return -EINVAL;
-			}
+		if (chan->type == IIO_LIGHT && !val)
 			ret = isl29018_set_integration_time(chip, val2);
-		}
 		break;
 	case IIO_CHAN_INFO_SCALE:
 		if (chan->type == IIO_LIGHT)