fix reshape test bug

mace/ops/reshape_test.cc

@@ -36,9 +36,10 @@ void TestReshape(const std::vector<index_t> &org_shape,
 
   // Add input data
   net.AddRandomInput<DeviceType::CPU, float>("Input", org_shape);
-  net.AddInputFromArray<DeviceType::CPU, int32_t>("Shape",
-                                                  {output_shape.size()},
-                                                  output_shape);
+  net.AddInputFromArray<DeviceType::CPU, int32_t>(
+      "Shape",
+      {static_cast<index_t>(output_shape.size())},
+      output_shape);
 
   // Run
   net.RunOp();