Nasty typo that was causing nondeterministic failures when running

MPI-2 dynamic tests that did not disconnect from the parent before
invoking MPI_FINALIZE.

This commit was SVN r6258.

src/communicator/comm_init.c

@@ -212,7 +212,7 @@ int ompi_comm_finalize(void)
     OBJ_DESTRUCT( &ompi_mpi_comm_world );
 
     if( ompi_mpi_comm_parent != &ompi_mpi_comm_null ) {
-       OBJ_DESTRUCT (&ompi_mpi_comm_parent);
+       OBJ_DESTRUCT (ompi_mpi_comm_parent);
     }
 
     OBJ_DESTRUCT( &ompi_mpi_comm_null );