hammer_flush_node
void hammer_flush_node(hammer_node_t node, int locked);
hammer_flush_node(node, 0);
hammer_flush_node(node, 0);
hammer_flush_node(parent->node, 0);
hammer_flush_node(node, locked + 1);
hammer_flush_node(node, locked + 1);
hammer_flush_node(node, 0);