feat: speed up fbank's lfr (#2246)

Tang Linjie

2024-11-30 8b1be8c3cba8987e9993619b46e59039ef3d6560

 examples/industrial_data_pretraining/llm_asr/demo_speech2text.sh

@@ -62,4 +62,3 @@

}&
done
wait