Upgrade benchmark (#2748)

* upgrade benchmark 2, test=develop

lite/api/benchmark.cc

@@ -151,6 +151,7 @@ void Run(const std::vector<std::vector<int64_t>>& input_shapes,
   ofs << "max = " << std::setw(12) << max_res;
   ofs << "average = " << std::setw(12) << avg_res;
   ofs << std::endl;
+  ofs.close();
 }
 #endif
 

lite/tools/benchmark.sh

@@ -72,7 +72,8 @@ for threads in ${NUM_THREADS_LIST[@]}; do
     done
     adb shell "echo >> $ANDROID_DIR/$RESULT_FILENAME"
 done
-
+adb shell "echo >> $ANDROID_DIR/$RESULT_FILENAME"
+adb shell "echo power_mode refer: 0 for big cluster, 1 for little cluster, 2 for all cores,  3 for no bind >> $ANDROID_DIR/$RESULT_FILENAME"
 # Adb pull benchmark result, show result
 adb pull $ANDROID_DIR/$RESULT_FILENAME .
 echo "\n--------------------------------------"