Fix error check in Reshape::propagate_types() (#219)

src/ngraph/ops/reshape.cpp

@@ -33,7 +33,7 @@ void Reshape::propagate_types()
         throw ngraph_error("Argument to reshape is missing type.");
     }
     auto arg_tensor_view_type = dynamic_pointer_cast<const TensorViewType>(arg_type);
-    if (nullptr == arg_type)
+    if (nullptr == arg_tensor_view_type)
     {
         throw ngraph_error("Argument to reshape is not a tensor view");
     }