iio: ad9523: Use 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 device attributes of the ad9523
driver.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211216185217.1054495-5-lars@metafoo.deSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/frequency/ad9523.c

@@ -551,7 +551,7 @@ static ssize_t ad9523_show(struct device *dev,
 	mutex_lock(&st->lock);
 	ret = ad9523_read(indio_dev, AD9523_READBACK_0);
 	if (ret >= 0) {
-		ret = sprintf(buf, "%d\n", !!(ret & (1 <<
+		ret = sysfs_emit(buf, "%d\n", !!(ret & (1 <<
 			(u32)this_attr->address)));
 	}
 	mutex_unlock(&st->lock);