tools/target_dec_fuzzer: Adjust maxpixels for indeo4

Fixes: Timeout (131sec -> 4sec)
Fixes: 15581/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_INDEO4_fuzzer-5651105515569152

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

tools/target_dec_fuzzer.c

@@ -137,6 +137,8 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
     case AV_CODEC_ID_GDV:       maxpixels /= 512; break;
         // Postprocessing in C
     case AV_CODEC_ID_HNM4_VIDEO:maxpixels /= 128; break;
+        // Cliping in C, generally slow even with small input
+    case AV_CODEC_ID_INDEO4:    maxpixels /= 128; break;
     }