Use logits instead of probs to compute supervised attention loss.
Use logits instead of probs to compute supervised attention loss.

PiperOrigin-RevId: 188254122

vthorsteinsson/tensor2tensor,vthorsteinsson/tensor2tensor,tensorflow/tensor2tensor,tensorflow/tensor2tensor,vthorsteinsson/tensor2tensor,tensorflow/tensor2tensor,tensorflow/tensor2tensor,tensorflow/tensor2tensor,vthorsteinsson/tensor2tensor