swift234

[Python] Fix two pylint warnings in swift-bench.py

Prior to this commit:

```
$ pylint utils/swift-bench.py 2>&1 | grep '(no-member)'
E:360,12: Instance of 'Test' has no 'results' member (no-member)
E:364,18: Instance of 'Test' has no 'output' member (no-member)
$
```

After this commit:

```
$ pylint utils/swift-bench.py 2>&1 | grep '(no-member)'
$
```