Incorrect changes

    * ACE/ace/Event_Handler.cpp:
    * ACE/ace/OS_Thread_Adapter.cpp:

Author: jwillemsen

ACE/ace/Event_Handler.cpp

@@ -231,7 +231,7 @@ ACE_Event_Handler::read_adapter (void *args)
   // cache the reactor pointer and use it here.
   r->notify ();
 
-  return nullptr;
+  return 0;
 }
 
 int

ACE/ace/OS_Thread_Adapter.cpp

@@ -69,7 +69,7 @@ ACE_OS_Thread_Adapter::invoke ()
         ACE_OS::thr_setcanceltype (val, &old);
     }
 
-  ACE_THR_FUNC_RETURN status = nullptr;
+  ACE_THR_FUNC_RETURN status = 0;
 
   ACE_SEH_TRY
     {