Fix error returning in `load` and skipping test `perlcritic`

I fixed following 2 issues:

* fix a returning error in `load`
* fix skipping test `perlcritic`


**fix a returning error in `load`**

I failed install/test in `cpanm Config::ENV` and `perl Build.PL && ./Build && .,/Build test` on Mac OSX (10.9).

So, I fixed for successful install/test. (maybe, also OK in linux)


**fix skipping test `perlcritic`**

Without Test::Perl::Critic, test fails as following:

```
$ perl Build.PL && ./Build && ./Build test
...
xt/98_perlcritic.t .. Can't locate Test/Perl/Critic.pm in @INC (@INC contains: /home/travis/build/issm/Config-ENV/blib/lib /home/travis/build/issm/Config-ENV/blib/arch /home/travis/build/issm/Config-ENV/_build/lib /home/travis/perl5/perlbrew/perls/5.14/lib/site_pe
rl/5.14.4/x86_64-linux /home/travis/perl5/perlbrew/perls/5.14/lib/site_perl/5.14.4 /home/travis/perl5/perlbrew/perls/5.14/lib/5.14.4/x86_64-linux /home/travis/perl5/perlbrew/perls/5.14/lib/5.14.4 .) at xt/98_perlcritic.t line 3.
BEGIN failed--compilation aborted at xt/98_perlcritic.t line 3.
xt/98_perlcritic.t .. Dubious, test returned 2 (wstat 512, 0x200)
No subtests run
xt/podspell.t ....... skipped: Test::Spelling is not installed.
```

So, I fixed to be able to skip.


**Why 2 issues in 1 PR?**

I wanted to send these PRs separately, but CI fails due to an issue of each other :)

* https://travis-ci.org/issm/Config-ENV/builds/44409177
* https://travis-ci.org/issm/Config-ENV/builds/44410028