balloon: don't bother with dentry_operations

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

drivers/virtio/virtio_balloon.c

@@ -761,11 +761,7 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info,
 static struct dentry *balloon_mount(struct file_system_type *fs_type,
 		int flags, const char *dev_name, void *data)
 {
-	static const struct dentry_operations ops = {
-		.d_dname = simple_dname,
-	};
-
-	return mount_pseudo(fs_type, "balloon-kvm:", NULL, &ops,
+	return mount_pseudo(fs_type, "balloon-kvm:", NULL, NULL,
 				BALLOON_KVM_MAGIC);
 }