Add godoc linter

[dfawley]

Since removing golint, we've had numerous occasions of missing docstrings. This seems like the consensus replacement for golint: https://github.com/mgechev/revive -- we should set it up to at least check the docstrings.

[purnesh42H]

Before we enforce revive, we need to fix existing lint issues caught in #7472 as part of vet check.

Its fine to change several files in a single PR if they all fix one type of issue or are otherwise related. However, be reasonable and try to keep the PRs small enough to make it not take a long time to review and avoid merge conflicts.

[janardhanvissa]

@purnesh42H Please assign me this issue.

[janardhanvissa]

@purnesh42H Right now, In the tests (vet) I'm getting like don't use an underscore in package name https://revive.run/r#var-naming.
It's not expecting underscore but by default as it's generating from the proto file like ("google.golang.org/grpc/reflection/test/grpc_testing_not_regenerate"). So, what need to do for further. Please suggest.

[janardhanvissa]

@purnesh42H Fixed some of the godoc-linter issues. Please review and let me know if any changes are required. Please find the PR below.
#7501

[janardhanvissa]

@purnesh42H Fixed linter issues for superfluous-else, increment-decrement, indent-error-flow, var-declaration. Please review the changes.

janardhanvissa#1

[janardhanvissa]

@purnesh42H Fixed below godoc linter issues. Please find the PRs below. Please let me know if any changes are required.

15 redefines-builtin-id
8 package-comments
8 empty-block
6 var-declaration
3 indent-error-flow
2 increment-decrement
1 superfluous-else

janardhanvissa#1
janardhanvissa#2
janardhanvissa#3

[purnesh42H]

@purnesh42H Fixed linter issues for superfluous-else, increment-decrement, indent-error-flow, var-declaration. Please review the changes.

janardhanvissa#1

Thanks. LGTM. Please open the. PR in main repo.

[janardhanvissa]

@purnesh42H Fixed below godoc linter issues and raised a PR to main repo.

6 var-declaration
3 indent-error-flow
2 increment-decrement
1 superfluous-else