iio: ina2xx-adc: sysfs_emit()

sysfs_emit() is preferred over raw s*printf() for sysfs attributes since it
knows about the sysfs buffer specifics and has some built-in checks for
size and alignment.

Use sysfs_emit() to format the custom `in_allow_async_readout` device
attribute of the ina2xx-adc driver.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211216185217.1054495-7-lars@metafoo.deSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ina2xx-adc.c

@@ -539,7 +539,7 @@ static ssize_t ina2xx_allow_async_readout_show(struct device *dev,
 {
 	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 
-	return sprintf(buf, "%d\n", chip->allow_async_readout);
+	return sysfs_emit(buf, "%d\n", chip->allow_async_readout);
 }
 
 static ssize_t ina2xx_allow_async_readout_store(struct device *dev,