Really fixes trac:623: there still is a difference between MPI::SEEK_SET

and ::SEEK_SET (duh); that's why it's listed in constants.h.  So put
that back and make it (static const int) rather than extern, and then
remove the instantiation from mpicxx.cc.  Ditto for the other 2.

This commit was SVN r20251.

The following Trac tickets were found above:
  Ticket 623 --> https://svn.open-mpi.org/trac/ompi/ticket/623

ompi/mpi/cxx/constants.h

@@ -249,6 +249,12 @@ OMPI_DECLSPEC extern const int MODE_SEQUENTIAL;
 
 OMPI_DECLSPEC extern const int DISPLACEMENT_CURRENT;
 
+#if OMPI_PROVIDE_MPI_FILE_INTERFACE && !defined(OMPI_IGNORE_CXX_SEEK) && OMPI_WANT_MPI_CXX_SEEK
+OMPI_DECLSPEC static const int SEEK_SET = ::SEEK_SET;
+OMPI_DECLSPEC static const int SEEK_CUR = ::SEEK_CUR;
+OMPI_DECLSPEC static const int SEEK_END = ::SEEK_END;
+#endif
+
 OMPI_DECLSPEC extern const int MAX_DATAREP_STRING;
 
 // one-sided constants

ompi/mpi/cxx/mpicxx.cc

@@ -275,12 +275,6 @@ const int MODE_SEQUENTIAL = MPI_MODE_SEQUENTIAL;
 
 const int DISPLACEMENT_CURRENT = MPI_DISPLACEMENT_CURRENT;
 
-#if OMPI_WANT_MPI_CXX_SEEK
-const int SEEK_SET = MPI_SEEK_SET;
-const int SEEK_CUR = MPI_SEEK_CUR;
-const int SEEK_END = MPI_SEEK_END;
-#endif
-
 const int MAX_DATAREP_STRING = MPI_MAX_DATAREP_STRING;
 #endif