Patch for /trunk/games.py

```
Resolve a stylistic incoherence by modifying Fig52Game's utility function so as 
it makes use of if_, as TicTacToe's utility function does.
```

Original issue reported on code.google.com by `Franck.Dernoncourt` on 13 Mar 2012 at 1:00

Attachments:
- [games.py.patch](https://storage.googleapis.com/google-code-attachments/aima-python/issue-30/comment-0/games.py.patch)
