free interfaces before freeing per_node pointers which hold the interface pointer

src/datawizard/interfaces/data_interface.c

@@ -224,6 +224,8 @@ void starpu_data_unregister(starpu_data_handle handle)
 		}
 	}
 
+	_starpu_data_free_interfaces(handle);
+
 	/* Destroy the data now */
 	unsigned node;
 	for (node = 0; node < STARPU_MAXNODES; node++)
@@ -241,8 +243,6 @@ void starpu_data_unregister(starpu_data_handle handle)
 
 	starpu_data_requester_list_delete(handle->req_list);
 
-	_starpu_data_free_interfaces(handle);
-
 	free(handle);
 }