RFR: defpath: normalize error format

[Robin Westberg]

On Mon, 21 Sep 2020 10:05:43 GMT, Erik Helin <ehelin at openjdk.org> wrote:

> Hi all,
> 
> please review this small patch that makes `git defpath` use the same error message as `git jcheck` and `git webrev`
> when not finding a local repository.
> Testing:
> - [x] Manual testing on Linux x64
> 
> Thanks,
> Erik

Looks good!

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Marked as reviewed by rwestberg (Reviewer).

PR: https://git.openjdk.java.net/skara/pull/833