fs: fix when path is buffer

[himself65]

#34514

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/32523/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/32524/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/32526/

[himself65]

Landed in 2c4f30d

[codebytere]

@himself65 could you please manually backport this to v14.x? It caused a new deterministic failure:

=== release test-worker-init-failure ===                                      
Path: parallel/test-worker-init-failure
child stdout: 

child stderr: events.js:291
      throw er; // Unhandled 'error' event
      ^

AssertionError [ERR_ASSERTION]: The input did not match the regular expression /EMFILE/. Input:

'ENOENT: no such file or directory, uv_cwd'

    at Worker.<anonymous> (/Users/codebytere/Developer/node/test/parallel/test-worker-init-failure.js:38:14)
    at Worker.emit (events.js:314:20)
    at Worker.[kOnErrorMessage] (internal/worker.js:238:10)
    at Worker.[kOnMessage] (internal/worker.js:248:37)
    at MessagePort.<anonymous> (internal/worker.js:167:57)
    at MessagePort.[nodejs.internal.kHybridDispatch] (internal/event_target.js:352:41)
    at MessagePort.exports.emitMessage (internal/per_context/messageport.js:18:26)
    at Worker.[kOnExit] (internal/worker.js:220:5)
    at Worker.<computed>.onexit (internal/worker.js:164:20)
Emitted 'error' event on process instance at:
    at emitUnhandledRejectionOrErr (internal/event_target.js:541:11)
    at MessagePort.[nodejs.internal.kHybridDispatch] (internal/event_target.js:356:9)
    at MessagePort.exports.emitMessage (internal/per_context/messageport.js:18:26)
    at Worker.[kOnExit] (internal/worker.js:220:5)
    at Worker.<computed>.onexit (internal/worker.js:164:20) {
  generatedMessage: true,
  code: 'ERR_ASSERTION',
  actual: 'ENOENT: no such file or directory, uv_cwd',
  expected: /EMFILE/,
  operator: 'match'
}
assert.js:103
  throw new AssertionError(obj);
  ^

AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:

1 !== 0

    at ChildProcess.<anonymous> (/Users/codebytere/Developer/node/test/parallel/test-worker-init-failure.js:64:12)
    at ChildProcess.<anonymous> (/Users/codebytere/Developer/node/test/common/index.js:363:15)
    at ChildProcess.emit (events.js:314:20)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:276:12) {
  generatedMessage: true,
  code: 'ERR_ASSERTION',
  actual: 1,
  expected: 0,
  operator: 'strictEqual'
}
Command: out/Release/node /Users/codebytere/Developer/node/test/parallel/test-worker-init-failure.js

and i'm not quite sure why.