!3861 [MS][LITE]fix benchmark inf error problem

Merge pull request !3861 from cjh9368/fix_benchmark_inf_bug

mindspore/lite/tools/benchmark/benchmark.cc

@@ -201,7 +201,6 @@ float Benchmark::CompareData(const std::string &nodeName, std::vector<int> msSha
     }
     std::cout << std::endl;
     if (meanError > 0.0f) {
-      errorCount = 0;
       meanError /= errorCount;
     }