[caffe2][torch] Clean up unused variable 'device' (#48600)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/48600
Fix this warning that pops up with clang and `-Wunused-variable`:
```
caffe2\torch\csrc\jit\frontend\schema_type_parser.cpp(153,30): warning: unused variable 'device' [-Wunused-variable]
```
Test Plan: Locally built & continuous integration
Reviewed By: eellison
Differential Revision: D25194298
fbshipit-source-id: 3af2895fcc96807a9df0ced60ec0af6b14dc0817
