Give line numbers in git-grep-based lints (#53733)
Summary:
Meant to make tasks like https://github.com/pytorch/pytorch/issues/53728 easier. The `-n` flag enables line numbers, and the `-o` flag reduces noise by only showing the part of the line that matched (which in this case is just the trailing whitespace).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53733
Test Plan:
```
$ git checkout e937db5dbaeaeae1134b02b3b78c43db3f6a91cd
```
Before:
```
$ (! git grep -I -l ' $' -- . ':(exclude)**/contrib/**' ':(exclude)third_party' || (echo "The above files have trailing spaces; please remove them"; false))
aten/src/ATen/native/cuda/BatchLinearAlgebra.cu
The above files have trailing spaces; please remove them
```
After:
```
$ (! git grep -I -no ' $' -- . ':(exclude)**/contrib/**' ':(exclude)third_party' || (echo "The above files have trailing spaces; please remove them"; false))
aten/src/ATen/native/cuda/BatchLinearAlgebra.cu:1972:
The above files have trailing spaces; please remove them
```
Reviewed By: mruberry
Differential Revision: D26953538
Pulled By: samestep
fbshipit-source-id: 5f7d48b79f1a02e5e5a09fe00316ec350cfc340e
