tools/target_dec_fuzzer: assume that discarded audio packets produced max samples

We do not know how many samples these produce as its not exported.
Alternatively we could export that but as long as its not we better
assume its more than 0 as otherwise the thresholds would not work

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

tools/target_dec_fuzzer.c

@@ -344,6 +344,11 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
             if (ec_pixels > maxpixels)
                 goto maximums_reached;
 
+            if (ctx->codec_type == AVMEDIA_TYPE_AUDIO &&
+                frame->nb_samples == 0 && !got_frame &&
+                (avpkt.flags & AV_PKT_FLAG_DISCARD))
+                nb_samples += ctx->max_samples;
+
             nb_samples += frame->nb_samples;
             if (nb_samples > maxsamples)
                 goto maximums_reached;