fix typo

Author: weihua916

examples/graphproppred/code2/README.md

@@ -3,7 +3,7 @@
 This repository includes the scripts for GNN baselines for `ogbg-code2` dataset.
 This code requires Pytorch Geometric version>=`1.5.0`.
 
-**Note (Feb 24, 2021)**: The older version `ogbg-code` is deprecated due to prediction target (i.e., method name) leakage in input AST. `ogbl-code2` (available from `ogb>=1.2.5` ) fixes this issue, where the method name and its recursive definition in AST are replace with a special token `_mask_`. The leaderboard results of `ogbg-code` and `ogbg-code2` are *not* comparable. 
+**Note (Feb 24, 2021)**: The older version `ogbg-code` is deprecated due to prediction target (i.e., method name) leakage in input AST. `ogbg-code2` (available from `ogb>=1.2.5` ) fixes this issue, where the method name and its recursive definition in AST are replace with a special token `_mask_`. The leaderboard results of `ogbg-code` and `ogbg-code2` are *not* comparable. 
 
 ## Training & Evaluation