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 <drv@mailo.com>
Link: https://lore.kernel.org/r/Y2uEIzebbM/Fs5Jz@qemulionSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/fieldbus/dev_core.c

@@ -28,7 +28,7 @@ static ssize_t online_show(struct device *dev, struct device_attribute *attr,
 {
 	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);
 
@@ -39,7 +39,7 @@ static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
 
 	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,
@@ -66,11 +66,8 @@ static ssize_t card_name_show(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);
 
@@ -79,7 +76,7 @@ static ssize_t read_area_size_show(struct device *dev,
 {
 	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);
 
@@ -88,7 +85,7 @@ static ssize_t write_area_size_show(struct device *dev,
 {
 	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);
 
@@ -116,7 +113,7 @@ static ssize_t fieldbus_type_show(struct device *dev,
 		break;
 	}
 
-	return sprintf(buf, "%s\n", t);
+	return sysfs_emit(buf, "%s\n", t);
 }
 static DEVICE_ATTR_RO(fieldbus_type);