Add missing include.

cmr=v1.8.2:ticket=trac:4639

This commit was SVN r31784.

The following Trac tickets were found above:
  Ticket 4639 --> https://svn.open-mpi.org/trac/ompi/ticket/4639

ompi/runtime/ompi_mpi_finalize.c

@@ -74,6 +74,7 @@
 #include "ompi/mca/mpool/base/mpool_base_tree.h"
 #include "ompi/mca/rcache/base/base.h"
 #include "ompi/mca/pml/base/pml_base_bsend.h"
+#include "ompi/mca/allocator/base/base.h"
 #include "ompi/runtime/params.h"
 #include "ompi/mca/dpm/base/base.h"
 #include "ompi/mca/pubsub/base/base.h"