[aten] remove variable set but never used warning (#34015)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34015
Remove warning
```
caffe2/aten/src/ATen/native/cuda/BatchLinearAlgebra.cu(1400): warning: variable "info" was set but never used
```
Test Plan: CI
Reviewed By: jianyuh
Differential Revision: D20181160
fbshipit-source-id: 31d44522a558fe7c2661a84dd6c35eb9d05b757a
