Collapsing lambdas onto too-long line

yapf (tested with 2c13f6f) turns the following:

```python
lambda: (
lambda: b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
)
```

into the following:

```python
lambda: (lambda: b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00")
```

Unfortunately this results in a line that is 81 characters long, while the former correctly fit into 80 characters.