Fixes another compile error when warnings are set

mojo/examples/wget/wget.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdio.h>
 
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/application_impl.h"
 #include "mojo/services/public/interfaces/network/network_service.mojom.h"
 #include "mojo/services/public/interfaces/network/url_loader.mojom.h"
@@ skipping 75 matching lines @@
       MojoResult result = ReadDataRaw(
           response_body_stream_.get(),
           buf,
           &num_bytes,
           MOJO_READ_DATA_FLAG_NONE);
       if (result == MOJO_RESULT_SHOULD_WAIT) {
         Wait(response_body_stream_.get(),
              MOJO_HANDLE_SIGNAL_READABLE,
              MOJO_DEADLINE_INDEFINITE);
       } else if (result == MOJO_RESULT_OK) {
-        fwrite(buf, num_bytes, 1, stdout);
+        assert(num_bytes == fwrite(buf, num_bytes, 1, stdout));

[darin (slow to review), 2014/06/28 05:29:00]

doesn't assert(x) compile to nothing in release builds?

       } else {
         break;
       }
     }
 
     printf("\n>>> EOF <<<\n");
   }
 
   NetworkServicePtr network_service_;
   URLLoaderPtr url_loader_;
   ScopedDataPipeConsumerHandle response_body_stream_;
 };
 
 }  // namespace examples
 
 // static
 ApplicationDelegate* ApplicationDelegate::Create() {
   return new examples::WGetApp();
 }
 
 }  // namespace mojo