ompi: invokes opal_cleanup() if ompi_mpi_finalize() when possible

As long as it is illegal to call MPI_T_init_thread() after MPI_Finalize(),
be gentle and release as much memory as possible in MPI_Finalize().
opal_cleanup() will be invoked again by the OPAL destructor, but will
do nothing since classes was set to NULL

ompi/runtime/ompi_mpi_finalize.c

@@ -17,6 +17,8 @@
  * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * Copyright (c) 2011      Sandia National Laboratories. All rights reserved.
  * Copyright (c) 2014-2016 Intel, Inc. All rights reserved.
+ * Copyright (c) 2016      Research Organization for Information Science
+ *                         and Technology (RIST). All rights reserved.
  *
  * $COPYRIGHT$
  *
@@ -485,6 +487,13 @@ int ompi_mpi_finalize(void)
         goto done;
     }
 
+    if (0 == opal_initialized) {
+        /* if there is no MPI_T_init_thread that has been MPI_T_finalize'd,
+         * then be gentle to the app and release all the memory now (instead
+         * of the opal library destructor */
+        opal_class_finalize();
+    }
+
     /* All done */
 
  done: