BIT-tensorflow-2020-15192

In Tensorflow before versions 2.2.1 and 2.3.1, if a user passes a list of strings to dlpack.to_dlpack there is a memory leak following an expected validation failure. The issue occurs because the status argument during validation failures is not properly checked. Since each of the above methods can return an error status, the status value must be checked before continuing. The issue is patched in commit 22e07fb204386768e5bcbea563641ea11f96ceb8 and is released in TensorFlow versions 2.2.1, or 2.3.1.