Wextra fix for Integration.cpp (#66321)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66321
Fixes
```
stderr: caffe2/aten/src/ATen/native/Integration.cpp:62:27: error: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'int64_t' (aka 'long') [-Werror,-Wsign-compare]
if (curr_shape.size() >= target_n_dim)
~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~
stderr: caffe2/aten/src/ATen/native/Integration.cpp:62:27: error: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'int64_t' (aka 'long') [-Werror,-Wsign-compare]
if (curr_shape.size() >= target_n_dim)
~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~
```
Test Plan: Sandcastle
Reviewed By: ngimel
Differential Revision: D31505347
fbshipit-source-id: 100b76215f78c3ce75bf4a993715a6767189747d
