class.c (gfc_find_derived_vtab): Disable ABI-breaking generation of the "_final" subroutine for now.

2012-09-03  Tobias Burnus  <burnus@net-b.de>

        * class.c (gfc_find_derived_vtab): Disable ABI-breaking
        generation of the "_final" subroutine for now.

From-SVN: r190872