fix benchmark.py

python/examples/bert/benchmark.py

@@ -70,7 +70,8 @@ def single_func(idx, resource):
                             os.getpid(),
                             int(round(b_start * 1000000)),
                             int(round(b_end * 1000000))))
-                result = client.predict(feed=feed_batch, fetch=fetch)
+                result = client.predict(
+                    feed=feed_batch, fetch=fetch, batch=True)
 
                 l_end = time.time()
                 if latency_flags: