g722: Return 8 bits per sample for g722 in av_get_bits_per_sample

This fixes a failing assert in ff_raw_read_header (in
fate-g722dec-1), where bits_per_coded_sample is set using this
function and is required to have a positive value.
Signed-off-by: Martin Storsjö <martin@martin.st>

libavcodec/utils.c

@@ -1107,6 +1107,7 @@ int av_get_bits_per_sample(enum CodecID codec_id){
     case CODEC_ID_ADPCM_MS:
     case CODEC_ID_ADPCM_YAMAHA:
         return 4;
+    case CODEC_ID_ADPCM_G722:
     case CODEC_ID_PCM_ALAW:
     case CODEC_ID_PCM_MULAW:
     case CODEC_ID_PCM_S8: