message: Fix the namespace for kCudaPlatformId, so cuda_platform.h is consistent with
  cuda_platform_id.h
diff: @@ -32,13 +32,14 @@ limitations under the License.
  #include "tensorflow/stream_executor/trace_listener.h"
  namespace stream_executor {
  -namespace gpu {
  -
  +namespace cuda {
  // Opaque and unique identifier for the CUDA platform plugin.
  // This is needed so that plugins can refer to/identify this platform without
  // instantiating a CudaPlatform object.
  extern const Platform::Id kCudaPlatformId;
  +} // namespace cuda
  +namespace gpu {
  // Cuda-specific platform plugin, registered as a singleton value via module
  // initializer.
  class CudaPlatform : public Platform {
  