flic: do not set sample_fmt

It is supposed to be set from lavc only.
Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavformat/flic.c

@@ -158,7 +158,6 @@ static int flic_read_header(AVFormatContext *s)
         ast->codec->codec_tag = 0;
         ast->codec->sample_rate = FLIC_TFTD_SAMPLE_RATE;
         ast->codec->channels = 1;
-        ast->codec->sample_fmt = AV_SAMPLE_FMT_U8;
         ast->codec->bit_rate = st->codec->sample_rate * 8;
         ast->codec->bits_per_coded_sample = 8;
         ast->codec->channel_layout = AV_CH_LAYOUT_MONO;