tools/target_dec_fuzzer: Adjust threshold for CDTOONS

Fixes: Timeout
Fixes: 48730/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CDTOONS_fuzzer-5124342899408896

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

tools/target_dec_fuzzer.c

@@ -213,6 +213,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     case AV_CODEC_ID_ARBC:        maxpixels  /= 1024;  break;
     case AV_CODEC_ID_ARGO:        maxpixels  /= 1024;  break;
     case AV_CODEC_ID_BINKVIDEO:   maxpixels  /= 32;    break;
+    case AV_CODEC_ID_CDTOONS:     maxpixels  /= 1024;  break;
     case AV_CODEC_ID_CFHD:        maxpixels  /= 16384; break;
     case AV_CODEC_ID_COOK:        maxsamples /= 1<<20; break;
     case AV_CODEC_ID_DFA:         maxpixels  /= 1024;  break;