init.el: Move cscope-setup to :config from :init

That way new install/setups of emacs work.

emacs.org

@@ -1150,7 +1150,7 @@ Instead of text might as well get a decent mode hook going here.
 #+BEGIN_SRC emacs-lisp
   (use-package xcscope
     :defer t
-    :init (progn (cscope-setup))
+    :config (progn (cscope-setup))
     )
 #+END_SRC