opal_finalize: fix minor memory leak

This string is strdup'ed in opal_init_util().

opal/runtime/opal_finalize.c

@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2008-2012 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2008-2015 Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2010-2013 Los Alamos National Security, LLC.
  *                         All rights reserved.
  * Copyright (c) 2013-2014 Intel, Inc. All rights reserved
@@ -109,6 +109,11 @@ opal_finalize_util(void)
     /* finalize the class/object system */
     opal_class_finalize();
 
+    if (NULL != opal_process_info.nodename) {
+        free(opal_process_info.nodename);
+        opal_process_info.nodename = NULL;
+    }
+
     return OPAL_SUCCESS;
 }