module: refactor redeclared variable

`homedir` was declared with `var` twice in the same scope in
`lib/module.js`. This change makes it a single declaration.

PR-URL: #4962
Reviewed-By: Brian White <[email protected]>
Reviewed-By: Minwoo Jung <[email protected]>
Reviewed-By: Roman Klauke <[email protected]>

Author: Trott

lib/module.js

@@ -446,10 +446,11 @@ Module.runMain = function() {
 Module._initPaths = function() {
   const isWindows = process.platform === 'win32';
 
+  var homeDir;
   if (isWindows) {
-    var homeDir = process.env.USERPROFILE;
+    homeDir = process.env.USERPROFILE;
   } else {
-    var homeDir = process.env.HOME;
+    homeDir = process.env.HOME;
   }
 
   var paths = [path.resolve(process.execPath, '..', '..', 'lib', 'node')];