tools: avoid using process.cwd in tools/lint-js

The first occurrence of path.join() can easily be replaced with
path.resolve().
The second occurrence should be unnecessary as ESLint will resolve the
path internally, and the old check probably did not work as intended
anyway.

PR-URL: #17121
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

tools/lint-js.js

@@ -13,7 +13,6 @@ const totalCPUs = require('os').cpus().length;
 const CLIEngine = require('./eslint').CLIEngine;
 const glob = require('./eslint/node_modules/glob');
 
-const cwd = process.cwd();
 const cliOptions = {
   rulePaths: rulesDirs,
   extensions: extensions,
@@ -82,9 +81,7 @@ if (cluster.isMaster) {
   if (i !== -1) {
     if (!process.argv[i + 1])
       throw new Error('Missing output filename');
-    var outPath = process.argv[i + 1];
-    if (!path.isAbsolute(outPath))
-      outPath = path.join(cwd, outPath);
+    const outPath = path.resolve(process.argv[i + 1]);
     fd = fs.openSync(outPath, 'w');
     outFn = function(str) {
       fs.writeSync(fd, str, 'utf8');
@@ -176,8 +173,6 @@ if (cluster.isMaster) {
       while (paths.length) {
         var dir = paths.shift();
         curPath = dir;
-        if (dir.indexOf('/') > 0)
-          dir = path.join(cwd, dir);
         const patterns = cli.resolveFileGlobPatterns([dir]);
         dir = path.resolve(patterns[0]);
         files = glob.sync(dir, globOptions);