Summary:
Meant to make tasks like pytorch#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: pytorch#53733

Test Plan:
```
$ git checkout e937db5
```

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

Summary:
malfet found a couple of these in #55346; this PR removes the rest and adds a lint that prevents them from being accidentally added again in the future. It also removes the `-o` flag added in #53733 (which was unnecessarily hiding context without reducing the number of lines of output), and updates the lint error messages to reflect that the individual line numbers are shown in the logs.

Pull Request resolved: #55465

Test Plan:
The "Lint / quick-checks" job in GitHub Actions should succeed on this PR. To verify that the lint does correctly find and error on non-breaking spaces, checkout ece0751 and run it locally:
```sh
(! git --no-pager grep -In $'\u00a0' -- . || (echo "The above lines have non-breaking spaces (U+00A0); please convert them to spaces (U+0020)"; false))
```
It should print over a hundred lines of output and exit with status 1.

Reviewed By: janeyx99

Differential Revision: D27622136

Pulled By: samestep

fbshipit-source-id: e7ffd5a9519093e7a0ffdf55e9291f63e21ce841

Summary:
Meant to make tasks like pytorch#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: pytorch#53733

Test Plan:
```
$ git checkout 6d7f62f
```

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

Summary:
malfet found a couple of these in pytorch#55346; this PR removes the rest and adds a lint that prevents them from being accidentally added again in the future. It also removes the `-o` flag added in pytorch#53733 (which was unnecessarily hiding context without reducing the number of lines of output), and updates the lint error messages to reflect that the individual line numbers are shown in the logs.

Pull Request resolved: pytorch#55465

Test Plan:
The "Lint / quick-checks" job in GitHub Actions should succeed on this PR. To verify that the lint does correctly find and error on non-breaking spaces, checkout 695699d and run it locally:
```sh
(! git --no-pager grep -In $'\u00a0' -- . || (echo "The above lines have non-breaking spaces (U+00A0); please convert them to spaces (U+0020)"; false))
```
It should print over a hundred lines of output and exit with status 1.

Reviewed By: janeyx99

Differential Revision: D27622136

Pulled By: samestep

fbshipit-source-id: e7ffd5a9519093e7a0ffdf55e9291f63e21ce841