staging: fieldbus: use sysfs_emit() in show functions

The show() methods should only use sysfs_emit() when formatting values
to be returned to the user space.
Ref: Documentation/filesystems/sysfs.rst
Issue identified by coccicheck.

Signed-off-by: Deepak R Varma <[e-mail]>
Link: https://lore.kernel.org/r/Y2uEIzebbM/Fs5Jz@qemulion
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/fieldbus/dev_core.c

···
 {
 	struct fieldbus_dev *fb = dev_get_drvdata(dev);
 
-	return sprintf(buf, "%d\n", !!fb->online);
+	return sysfs_emit(buf, "%d\n", !!fb->online);
 }
 static DEVICE_ATTR_RO(online);
 
···
 
 	if (!fb->enable_get)
 		return -EINVAL;
-	return sprintf(buf, "%d\n", !!fb->enable_get(fb));
+	return sysfs_emit(buf, "%d\n", !!fb->enable_get(fb));
 }
 
 static ssize_t enabled_store(struct device *dev, struct device_attribute *attr,
···
 {
 	struct fieldbus_dev *fb = dev_get_drvdata(dev);
 
-	/*
-	 * card_name was provided by child driver, could potentially be long.
-	 * protect against buffer overrun.
-	 */
-	return snprintf(buf, PAGE_SIZE, "%s\n", fb->card_name);
+	/* card_name was provided by child driver. */
+	return sysfs_emit(buf, "%s\n", fb->card_name);
 }
 static DEVICE_ATTR_RO(card_name);
 
···
 {
 	struct fieldbus_dev *fb = dev_get_drvdata(dev);
 
-	return sprintf(buf, "%zu\n", fb->read_area_sz);
+	return sysfs_emit(buf, "%zu\n", fb->read_area_sz);
 }
 static DEVICE_ATTR_RO(read_area_size);
 
···
 {
 	struct fieldbus_dev *fb = dev_get_drvdata(dev);
 
-	return sprintf(buf, "%zu\n", fb->write_area_sz);
+	return sysfs_emit(buf, "%zu\n", fb->write_area_sz);
 }
 static DEVICE_ATTR_RO(write_area_size);
 
···
 		break;
 	}
 
-	return sprintf(buf, "%s\n", t);
+	return sysfs_emit(buf, "%s\n", t);
 }
 static DEVICE_ATTR_RO(fieldbus_type);