opal/progress: fix non debug builds

this bug was introduced in open-mpi/ompi@64b695669a

Thanks Pavel (Pasha) Shamis for reporting this issue

opal/runtime/opal_progress.c

@@ -12,7 +12,7 @@
  *                         All rights reserved.
  * Copyright (c) 2006-2014 Los Alamos National Security, LLC.  All rights
  *                         reserved.
- * Copyright (c) 2015      Research Organization for Information Science
+ * Copyright (c) 2015-2016 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  *
  * $COPYRIGHT$
@@ -222,6 +222,8 @@ opal_progress_event_users_increment(void)
     val = opal_atomic_add_32(&num_event_users, 1);
 
     OPAL_OUTPUT((debug_output, "progress: event_users_increment setting count to %d", val));
+#else
+    (void)opal_atomic_add_32(&num_event_users, 1);
 #endif
 
 #if OPAL_PROGRESS_USE_TIMERS
@@ -237,11 +239,13 @@ opal_progress_event_users_increment(void)
 void
 opal_progress_event_users_decrement(void)
 {
-#if OPAL_ENABLE_DEBUG
+#if OPAL_ENABLE_DEBUG || ! OPAL_PROGRESS_USE_TIMERS
     int32_t val;
     val = opal_atomic_sub_32(&num_event_users, 1);
 
     OPAL_OUTPUT((debug_output, "progress: event_users_decrement setting count to %d", val));
+#else
+    (void)opal_atomic_sub_32(&num_event_users, 1);
 #endif
 
 #if !OPAL_PROGRESS_USE_TIMERS