chore(createWriteStream): coding style

lib/api/createWriteStream.js

@@ -15,8 +15,7 @@ module.exports = function createWriteStream(path, options, cb) {
 
   var createDisposition;
   var flags = options != null && options.flags;
-  if (flags == null) {
-  } else if (flags === 'r+') {
+  if (flags === 'r+') {
     createDisposition = constants.FILE_OPEN;
   } else if (flags === 'w' || flags === 'w+') {
     createDisposition = constants.FILE_OVERWRITE_IF;
@@ -49,7 +48,7 @@ module.exports = function createWriteStream(path, options, cb) {
             Offset: offset.toBuffer(),
           },
           connection,
-          function(err, result) {
+          function(err) {
             if (err != null) {
               return cb(err);
             }