iio: chemical: scd30_core: use sysfs_emit() to instead of scnprintf()

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the
value to be returned to user space.

Signed-off-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/chemical/scd30_core.c

···
 	ssize_t len = 0;
 
 	do {
-		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%09u ", 1000000000 / i);
+		len += sysfs_emit_at(buf, len, "0.%09u ", 1000000000 / i);
 		/*
 		 * Not all values fit PAGE_SIZE buffer hence print every 6th
 		 * (each frequency differs by 6s in time domain from the
···
 	ret = scd30_command_read(state, CMD_ASC, &val);
 	mutex_unlock(&state->lock);
 
-	return ret ?: sprintf(buf, "%d\n", val);
+	return ret ?: sysfs_emit(buf, "%d\n", val);
 }
 
 static ssize_t calibration_auto_enable_store(struct device *dev, struct device_attribute *attr,
···
 	ret = scd30_command_read(state, CMD_FRC, &val);
 	mutex_unlock(&state->lock);
 
-	return ret ?: sprintf(buf, "%d\n", val);
+	return ret ?: sysfs_emit(buf, "%d\n", val);
 }
 
 static ssize_t calibration_forced_value_store(struct device *dev, struct device_attribute *attr,