Do I need to free pfxBitstream->Data when done with it?

I currently have mfxBitstream *pMfxBitstream that comes out of EncodeFrameAsync

At that point pfxBitstream->data contains data, however after writing that data to a file or copying it somewhere else, I no longer need it

Is setting pMfxBitstream->DataLength = 0; enough as shown by the example?  Or should I also free pMfxBitstream->Data if I intent to use it repeatedly and avoid memory leaks?  Or would freeing it potentially cause problems?

Thank you.