iio: lm3533: 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 lm3533
driver.  Note this driver was using scnprintf correctly so this change
is about ensuring examples of code that might get cut and paste into new
drivers are using current best practice.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211216185217.1054495-8-lars@metafoo.deSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/lm3533-als.c

@@ -417,7 +417,7 @@ static ssize_t show_thresh_either_en(struct device *dev,
 		enable = 0;
 	}
 
-	return scnprintf(buf, PAGE_SIZE, "%u\n", enable);
+	return sysfs_emit(buf, "%u\n", enable);
 }
 
 static ssize_t store_thresh_either_en(struct device *dev,
@@ -474,7 +474,7 @@ static ssize_t show_zone(struct device *dev,
 	if (ret)
 		return ret;
 
-	return scnprintf(buf, PAGE_SIZE, "%u\n", zone);
+	return sysfs_emit(buf, "%u\n", zone);
 }
 
 enum lm3533_als_attribute_type {
@@ -530,7 +530,7 @@ static ssize_t show_als_attr(struct device *dev,
 	if (ret)
 		return ret;
 
-	return scnprintf(buf, PAGE_SIZE, "%u\n", val);
+	return sysfs_emit(buf, "%u\n", val);
 }
 
 static ssize_t store_als_attr(struct device *dev,