Wrapper suppresses exit code 2 even when it is an error

In https://github.com/hashicorp/setup-terraform/pull/125 the wrapper was updated to consider an exit code of 2 to be a success, because of a quirk of the `plan` command. But `fmt` can also return exit code 2, and it is not considered a success in that case. An example is if you call `terraform fmt -check -recursive ` and `` is not present. In that case a GitHub action running that command will succeed (if you use the wrapper) even though the command failed.

Start by reviewing the wrapper change described in pull request 125 and reproduce `terraform fmt -check -recursive ` with a missing directory. Done means an exit code of 2 from `fmt` still fails the GitHub Actions command, while the existing `plan` behavior remains intact.

Written by the indexing model from the issue text.