avcodec/dstdec: Check read_table() for failure

Fixes: Timeout (too long -> 42sec)
Fixes: 18181/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DST_fuzzer-5736646250594304

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

libavcodec/dstdec.c

@@ -302,11 +302,15 @@ static int decode_frame(AVCodecContext *avctx, void *data,
 
     /* Filter Coef Sets (10.12) */
 
-    read_table(gb, &s->fsets, fsets_code_pred_coeff, 7, 9, 1, 0);
+    ret = read_table(gb, &s->fsets, fsets_code_pred_coeff, 7, 9, 1, 0);
+    if (ret < 0)
+        return ret;
 
     /* Probability Tables (10.13) */
 
-    read_table(gb, &s->probs, probs_code_pred_coeff, 6, 7, 0, 1);
+    ret = read_table(gb, &s->probs, probs_code_pred_coeff, 6, 7, 0, 1);
+    if (ret < 0)
+        return ret;
 
     /* Arithmetic Coded Data (10.11) */