Fixed incorrect comments.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%402814

examples/pipe_ex_2.cpp

@@ -72,10 +72,10 @@ public:
         message_pipe.wait_until_empty();
 
         // Now disable the message_pipe.  Doing this will cause all calls to 
-        // message_pipe.dequeue() to return false so our threads will terminate
+        // message_pipe.dequeue() to return false so our thread will terminate
         message_pipe.disable();
 
-        // now block until all the threads have terminated
+        // now block until our thread has terminated
         wait();
     }