http,util: fix typos in comments

Fix several typos in comments.

PR-URL: https://github.com/nodejs/node/pull/5279
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/_http_server.js

@@ -486,7 +486,7 @@ function connectionListener(socket) {
     }
 
     // When we're finished writing the response, check if this is the last
-    // respose, if so destroy the socket.
+    // response, if so destroy the socket.
     res.on('finish', resOnFinish);
     function resOnFinish() {
       // Usually the first incoming element should be our request.  it may