Remove using statement (#4286)

Co-authored-by: Scott Cyphers <diyessi@users.noreply.github.com>

src/ngraph/runtime/tensor.hpp

@@ -119,7 +119,5 @@ namespace ngraph
             std::shared_ptr<ngraph::descriptor::Tensor> m_descriptor;
             bool m_stale;
         };
-
-        using TensorViewPtrs = std::vector<std::shared_ptr<Tensor>>;
     }
 }