No method to free data allocated by mp3dec_load_buf

[samhattangady]

mp3dec_load_buf and mp3dec_load_cb allocate some data by making a call to malloc. There is no method for us to call to free that data.

I wrote a small function for that.

void mp3dec_free(mp3dec_file_info_t *info) 
{
    free((void*)info->buffer);
}