avcodec/cbs_av1: abort when written inferred values don't match

If this happens, it's a sign of parsing issues earlier in the process, or
misuse by the calling module.

Prevents writing invalid bitstreams.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/cbs_av1.c

@@ -711,10 +711,11 @@ static size_t cbs_av1_get_payload_bytes_left(GetBitContext *gbc)
 
 #define infer(name, value) do { \
         if (current->name != (value)) { \
-            av_log(ctx->log_ctx, AV_LOG_WARNING, "Warning: " \
+            av_log(ctx->log_ctx, AV_LOG_ERROR, \
                    "%s does not match inferred value: " \
                    "%"PRId64", but should be %"PRId64".\n", \
                    #name, (int64_t)current->name, (int64_t)(value)); \
+            return AVERROR_INVALIDDATA; \
         } \
     } while (0)