iio: magnetometer: ak8975: avoid using temporary variable

Avoid using temporary variable in ak8975_read_axis(). With that being done,
the clamp_t() call becomes idiomatic in the driver and can be factored out
to a helper later on (and if needed).

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Joshua Crofts <joshua.crofts1@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Author: andy-shev

drivers/iio/magnetometer/ak8975.c

@@ -741,7 +741,6 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
 	const struct i2c_client *client = data->client;
 	const struct ak_def *def = data->def;
 	__le16 rval;
-	u16 buff;
 	int ret;
 
 	pm_runtime_get_sync(&data->client->dev);
@@ -778,8 +777,8 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
 	pm_runtime_put_autosuspend(&data->client->dev);
 
 	/* Swap bytes and convert to valid range. */
-	buff = le16_to_cpu(rval);
-	*val = clamp_t(s16, buff, -def->range, def->range);
+	*val = clamp_t(s16, le16_to_cpu(rval), -def->range, def->range);
+
 	return IIO_VAL_INT;
 
 exit: