!2407 change Q.BNTrainingReduce() to P.BNTrainingReduce()

Merge pull request !2407 from chenzhongming/r0.3

mindspore/nn/layer/quant.py

@@ -79,7 +79,7 @@ class BatchNormFoldCell(Cell):
             self.bn_train = Q.BatchNormFold(momentum, epsilon, is_training=True, freeze_bn=freeze_bn)
             self.bn_infer = Q.BatchNormFold(momentum, epsilon, is_training=False, freeze_bn=freeze_bn)
         else:
-            self.bn_reduce = Q.BNTrainingReduce()
+            self.bn_reduce = P.BNTrainingReduce()
             self.bn_update = Q.BatchNormFoldD(momentum, epsilon, is_training=True, freeze_bn=freeze_bn)
 
     def construct(self, x, mean, variance, global_step):