Restore fast path in OnnxifiOp::adjustOutputBatchSize (#52498)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52498
If `max_shape[dim]` equals to `real_shape[dim]`, we shouldn't need to adjust dim in terms of output slicing. Consider the case, when we have output compiled at [10, 4] and real input is [5, 4], we only need to adjust outermost dim (10->5) for the second dim, we don't need to do anything. Thus this should fall to fast path.
Test Plan:
```
buck test glow/fb/test:test_onnxifinnpi
```
Reviewed By: khabinov
Differential Revision: D26542773
fbshipit-source-id: 0475e0a1c35be6f28ccc63dc69cb0b5acf695141
