Cygwin: dumper: use void* in place of PTR

The definition of PTR has been dropped from newer versions
of ansidecl.h.

Convert definition of print_section_name to use void * instead,
as required by bfd_map_over_sections.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/utils/dumper.cc

@@ -142,7 +142,7 @@ dumper::sane ()
 }
 
 void
-print_section_name (bfd* abfd, asection* sect, PTR obj)
+print_section_name (bfd* abfd, asection* sect, void* obj)
 {
   deb_printf (" %s", get_section_name (abfd, sect));
 }