test: replace fixturesDir with fixtures methods

PR-URL: nodejs/node#15833
Reviewed-By: Ryan Graham <r.m.graham@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>

test/parallel/test-http2-respond-file-fd-errors.js

@@ -3,8 +3,8 @@
 const common = require('../common');
 if (!common.hasCrypto)
   common.skip('missing crypto');
+const fixtures = require('../common/fixtures');
 const http2 = require('http2');
-const path = require('path');
 const fs = require('fs');
 
 const {
@@ -29,7 +29,7 @@ const types = {
   symbol: Symbol('test')
 };
 
-const fname = path.resolve(common.fixturesDir, 'elipses.txt');
+const fname = fixtures.path('elipses.txt');
 const fd = fs.openSync(fname, 'r');
 
 const server = http2.createServer();