Wrong argument name in soma_processor

[simon-schaefer]

Hi,

first of all, thank you for publishing and releasing such an awesome work to the public!
While looking at the code I have noticed a small mismatch of function arguments. In soma/src/soma/tools/soma_processor.py:451 you call the function write_mocap_c3d with the wrong argument. It should be out_mocap_fname not out_c3d_fname, so

    if rt_cfg.save_c3d:
        c3d_out_fname = rt_cfg.dirs.mocap_out_fname.replace('.pkl', '.c3d')
        nan_replaced_labels = [l if l != 'nan' else '*{}'.format(i) for i, l in enumerate(results['labels'])]
        write_mocap_c3d(out_mocap_fname=c3d_out_fname,
                        markers=results['markers'],
                        labels=nan_replaced_labels,
                        frame_rate=soma_labeler.mocap_frame_rate)
        logger.info(f'Created {c3d_out_fname}')

Happy to do a small PR to fix this as well :)