test: http2-respond-file-errors to fixtures module

Replace common.fixturesDir with fixtures in
test-http2-respond-file-errors.js.

PR-URL: https://github.com/nodejs/node/pull/16004
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

test/parallel/test-http2-respond-file-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 {
   HTTP2_HEADER_CONTENT_TYPE,
@@ -28,7 +28,7 @@ const types = {
   symbol: Symbol('test')
 };
 
-const fname = path.resolve(common.fixturesDir, 'elipses.txt');
+const fname = fixtures.path('elipses.txt');
 
 const server = http2.createServer();