fs: configfs: don't return anything from drop_link

Documentation/filesystems/configfs/configfs.txt says:

"When unlink(2) is called on the symbolic link, the source item is
notified via the ->drop_link() method.  Like the ->drop_item() method,
this is a void function and cannot return failure."

The ->drop_item() is indeed a void function, the ->drop_link() is
actually not. This, together with the fact that the value of ->drop_link()
is silently ignored suggests, that it is the ->drop_link() return
type that should be corrected and changed to void.

This patch changes drop_link() signature and all its users.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
[hch: reverted reformatting of some code]
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/usb/gadget/configfs.c

@@ -408,7 +408,7 @@ out:
 	return ret;
 }
 
-static int config_usb_cfg_unlink(
+static void config_usb_cfg_unlink(
 	struct config_item *usb_cfg_ci,
 	struct config_item *usb_func_ci)
 {
@@ -437,12 +437,11 @@ static int config_usb_cfg_unlink(
 			list_del(&f->list);
 			usb_put_function(f);
 			mutex_unlock(&gi->lock);
-			return 0;
+			return;
 		}
 	}
 	mutex_unlock(&gi->lock);
 	WARN(1, "Unable to locate function to unbind\n");
-	return 0;
 }
 
 static struct configfs_item_operations gadget_config_item_ops = {
@@ -865,7 +864,7 @@ out:
 	return ret;
 }
 
-static int os_desc_unlink(struct config_item *os_desc_ci,
+static void os_desc_unlink(struct config_item *os_desc_ci,
 			  struct config_item *usb_cfg_ci)
 {
 	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
@@ -878,7 +877,6 @@ static int os_desc_unlink(struct config_item *os_desc_ci,
 	cdev->os_desc_config = NULL;
 	WARN_ON(gi->composite.gadget_driver.udc_name);
 	mutex_unlock(&gi->lock);
-	return 0;
 }
 
 static struct configfs_item_operations os_desc_ops = {