close fuse_all_reduce_ops in the low level quant usage. (#3876)

PaddleSlim/quant_low_level_api/quant.py

@@ -257,6 +257,7 @@ def train(args):
     build_strategy = fluid.BuildStrategy()
     build_strategy.memory_optimize = False
     build_strategy.enable_inplace = False
+    build_strategy.fuse_all_reduce_ops = False
     binary = fluid.CompiledProgram(main_graph.graph).with_data_parallel(
         loss_name=train_cost.name, build_strategy=build_strategy)
     test_prog = test_graph.to_program()