avcodec/bitpacked: add missing comma to codec tags

Fixes: array end overread
Fixes: 22395/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BITPACKED_fuzzer-5760940300828672

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: James Darnley <james.darnley@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/bitpacked.c

@@ -147,7 +147,7 @@ AVCodec ff_bitpacked_decoder = {
     .decode = bitpacked_decode,
     .capabilities = AV_CODEC_CAP_EXPERIMENTAL,
     .codec_tags     = (const uint32_t []){
-        MKTAG('U', 'Y', 'V', 'Y')
+        MKTAG('U', 'Y', 'V', 'Y'),
         FF_CODEC_TAGS_END,
     },
 };