fix spelling

lib/fs.js

@@ -601,7 +601,7 @@ function errnoException(errorno, syscall) {
 }
 
 
-function FSWather() {
+function FSWatcher() {
   var self = this;
   var FSEvent = process.binding('fs_event_wrap').FSEvent;
   this._handle = new FSEvent();
@@ -614,9 +614,9 @@ function FSWather() {
     }
   };
 }
-util.inherits(FSWather, EventEmitter);
+util.inherits(FSWatcher, EventEmitter);
 
-FSWather.prototype.start = function(filename, persistent) {
+FSWatcher.prototype.start = function(filename, persistent) {
   var r = this._handle.start(filename, persistent);
 
   if (r) {
@@ -625,7 +625,7 @@ FSWather.prototype.start = function(filename, persistent) {
   }
 };
 
-FSWather.prototype.close = function() {
+FSWatcher.prototype.close = function() {
   this._handle.close();
 };
 
@@ -648,7 +648,7 @@ fs.watch = function(filename) {
 
   if (options.persistent === undefined) options.persistent = true;
 
-  watcher = new FSWather();
+  watcher = new FSWatcher();
   watcher.start(filename, options.persistent);
 
   watcher.addListener('change', listener);