test: skip test-fs-access if root

[danbev]

Currently, if this test is run as the root user the following
failure will occur:

=== release test-fs-access ===
Path: parallel/test-fs-access
(node:46733) internal/test/binding: These APIs are for internal testing
only. Do not use them.
Can't clean tmpdir: /root/node/test/.tmp.522
Files blocking: [ 'read_only_file', 'read_write_file' ]

/root/node/test/common/tmpdir.js:136
    throw e;
    ^

Error: EACCES: permission denied, rmdir '/root/node/test/.tmp.522'
    at Object.rmdirSync (fs.js:693:3)
    at rmdirSync (/root/node/test/common/tmpdir.js:72:8)
    at rimrafSync (/root/node/test/common/tmpdir.js:41:7)
    at process.onexit (/root/node/test/common/tmpdir.js:121:5)
    at process.emit (events.js:214:15) {
  errno: -13,
  syscall: 'rmdir',
  code: 'EACCES',
  path: '/root/node/test/.tmp.522'
}
Command: ./node --expose-internals test/parallel/test-fs-access.js

This commit adds a root user check and skips this test if running as the
user root.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/24945/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/24948/

[Trott]

Totally optional suggestion:

Suggested change

	common.skip('as this test should not be run as `root`');
	common.skip('test needs to be run as an unprivileged user');

[danbev]

Thanks, I like your suggestion and I'm happy to change this. But perhaps this should be done in a follow up PR as there are a couple of these skips that I've added in the past with this wording and changing them all would make the output more consistent. Does that sound alright?

[Trott]

Sure, that sounds fine. It was a totally optional suggestion anyway and I wouldn't mind if you ignored it completely. Do it now, do it later, don't do it at all, it's all good by me.

[Trott]

Landed in f7321dc