parallelize the generation script

[saikrishnarallabandi]

Right now the prediction script is doing with bsz=1

https://github.com/saikrishnarallabandi/falkon/blob/master/tasks/speech/antispoofing/baseline/local/get_predictions.py

When parallelized, filename has to be kept in mind.

[saikrishnarallabandi]

@peterwu99