message: fix unbalanced delimiter in benchmark_model doc
  as reported in
  there is unbalanced delimiter `"`
diff: @@ -32,7 +32,7 @@ adb push bazel-bin/tensorflow/tools/benchmark/benchmark_model /data/local/tmp
  (4) Run the benchmark. For example:
  ```
  -adb shell "/data/local/tmp/benchmark_model \
  +adb shell /data/local/tmp/benchmark_model \
  --graph=/data/local/tmp/tensorflow_inception_graph.pb \
  --input_layer="input:0" \
  --input_layer_shape="1,224,224,3" \
  