HID: hiddev: fix use after free in hiddev_release

There are a couple use after free bugs here.
Signed-off-by: Dan Carpenter <error27@gmail.com>
[jkosina@suse.cz: removed already fixed hunk]
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/usbhid/hiddev.c

@@ -248,12 +248,15 @@ static int hiddev_release(struct inode * inode, struct file * file)
 			usbhid_close(list->hiddev->hid);
 			usbhid_put_power(list->hiddev->hid);
 		} else {
+			mutex_unlock(&list->hiddev->existancelock);
 			kfree(list->hiddev);
+			kfree(list);
+			return 0;
 		}
 	}
 
-	kfree(list);
 	mutex_unlock(&list->hiddev->existancelock);
+	kfree(list);
 
 	return 0;
 }