[BUG] FreeSurfer version returns None

### Summary

```Python
>>> from nipype.interfaces.freesurfer import ReconAll
>>> ReconAll().version is None
True
>>> from nipype.interfaces.fsl import BET
>>> BET().version
'5.0.9'
```
### Expected behavior
```Python
>>> from nipype.interfaces.freesurfer import ReconAll
>>> ReconAll().version is None
False
```

### Environment
FMRIPREP containers and pip installed environment.