objspace_dump.c: dc is no longer used [ci skip]

* ext/objspace/objspace_dump.c (heap_i): remove no longer used
  variable.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56177 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/objspace/objspace_dump.c

@@ -318,7 +318,6 @@ dump_object(VALUE obj, struct dump_config *dc)
 static int
 heap_i(void *vstart, void *vend, size_t stride, void *data)
 {
-    struct dump_config *dc = (struct dump_config *)data;
     VALUE v = (VALUE)vstart;
     for (; v != (VALUE)vend; v += stride) {
 	if (RBASIC(v)->flags)