fix EagerTensor.Device property.

src/TensorFlowNET.Core/Eager/EagerTensor.cs

@@ -11,6 +11,7 @@ namespace Tensorflow.Eager
         Status status = new Status();
         TFE_TensorHandle tfe_tensor_handle;
         public IntPtr EagerTensorHandle { get; set; }
+        public override string Device => c_api.StringPiece(c_api.TFE_TensorHandleDeviceName(tfe_tensor_handle, status));
 
         public EagerTensor(IntPtr handle) : base(handle)
         {

src/TensorFlowNET.Core/Eager/c_api.eager.cs

@@ -246,6 +246,7 @@ namespace Tensorflow
         [DllImport(TensorFlowLibName)]
         public static extern TF_Tensor TFE_TensorHandleResolve(IntPtr h, IntPtr status);
 
+
         /// <summary>
         /// This function will block till the operation that produces `h` has completed.
         /// </summary>

src/TensorFlowNET.Core/Tensors/Tensor.cs

@@ -82,7 +82,7 @@ namespace Tensorflow
         /// <summary>
         ///     The name of the device on which this tensor will be produced, or null.
         /// </summary>
-        public string Device => op.Device;
+        public virtual string Device => op.Device;
         public int[] dims => shape;
 
         /// <summary>