test: replace common.fixturesDir with fixtures

PR-URL: nodejs/node#16015
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-repl-tab-complete.js

@@ -23,11 +23,12 @@
 
 const common = require('../common');
 const assert = require('assert');
+const fixtures = require('../common/fixtures');
 
 // We have to change the directory to ../fixtures before requiring repl
 // in order to make the tests for completion of node_modules work properly
 // since repl modifies module.paths.
-process.chdir(common.fixturesDir);
+process.chdir(fixtures.fixturesDir);
 
 const repl = require('repl');