Remove warning in batch_norm_op (#19260)

paddle/fluid/operators/batch_norm_op.cc

@@ -245,8 +245,8 @@ class BatchNormKernel<platform::CPUDeviceContext, T>
           variance_out->mutable_data<T>(ctx.GetPlace()), C);
 
       if ((N * sample_size) == 1) {
-        LOG(WARNING) << "Only 1 element in normalization dimension, "
-                     << "we skip the batch norm calculation, let y = x.";
+        // Only 1 element in normalization dimension,
+        // we skip the batch norm calculation, let y = x.
         framework::TensorCopy(*x, ctx.GetPlace(), y);
         return;
       }

paddle/fluid/operators/batch_norm_op.cu

@@ -152,8 +152,8 @@ class BatchNormKernel<platform::CUDADeviceContext, T>
       functor(dev_ctx, saved_variance, static_cast<BatchNormParamType<T>>(0));
 
       if ((N * H * W * D) == 1) {
-        LOG(WARNING) << "Only 1 element in normalization dimension, "
-                     << "we skip the batch norm calculation, let y = x.";
+        // Only 1 element in normalization dimension,
+        // skip the batch norm calculation, let y = x.
         framework::TensorCopy(*x, ctx.GetPlace(), y);
       } else {
         double this_factor = 1. - momentum;