Simplify buffering

There is no way more than one read event would be buffered.

lib/fs.js

@@ -395,7 +395,7 @@ var FileReadStream = exports.FileReadStream = function(path, options) {
 
   var
     self = this,
-    buffer = [];
+    buffer = null;
 
   function read() {
     if (!self.readable || self.paused) {
@@ -411,7 +411,7 @@ var FileReadStream = exports.FileReadStream = function(path, options) {
 
       // do not emit events if the stream is paused
       if (self.paused) {
-        buffer.push(data);
+        buffer = data;
         return;
       }
 
@@ -450,15 +450,9 @@ var FileReadStream = exports.FileReadStream = function(path, options) {
   this.resume = function() {
     this.paused = false;
 
-    // emit any buffered read events before continuing
-    var data;
-    while (!this.paused) {
-      data = buffer.shift();
-      if (data === undefined) {
-        break;
-      }
-
-      self.emit('data', data);
+    if (buffer !== null) {
+      self.emit('data', buffer);
+      buffer = null;
     }
 
     read();