Fix API break on bdev_specs

src/lxc/lxccontainer.h

@@ -857,11 +857,11 @@ struct bdev_specs {
 		char *lv; /*!< LVM Logical Volume name */
 		char *thinpool; /*!< LVM thin pool to use, if any */
 	} lvm;
+	char *dir; /*!< Directory path */
 	struct {
 		char *rbdname; /*!< RBD image name */
 		char *rbdpool; /*!< Ceph pool name */
 	} rbd;
-	char *dir; /*!< Directory path */
 };
 
 /*!