Don't write parent node twice
Don't write parent node twice

Parent node has been written new_node_write, no need to write it again.

Signed-off-by: Rock Lee <b2814929313d0a05588e00c41347da0741d1b191@gmail.com>

begeekmyfriend/bplustree,begeekmyfriend/bplustree,begeekmyfriend/bplustree