add sync_bn

dygraph/models/hrnet.py

@@ -18,7 +18,8 @@ import paddle
 import paddle.fluid as fluid
 from paddle.fluid.param_attr import ParamAttr
 from paddle.fluid.layer_helper import LayerHelper
-from paddle.fluid.dygraph.nn import Conv2D, Pool2D, BatchNorm, Linear
+from paddle.fluid.dygraph.nn import Conv2D, Pool2D, Linear
+from paddle.fluid.dygraph import SyncBatchNorm as BatchNorm
 
 __all__ = [
     "HRNet_W18_Small_V1", "HRNet_W18_Small_V2", "HRNet_W18", "HRNet_W30",