master d58e3b3: Fix out-of-tree make check

[Glenn Morris]

branch: master
commit d58e3b3997228423b81df49035bd584fa1918f13
Author: Glenn Morris <rgm@gnu.org>
Commit: Glenn Morris <rgm@gnu.org>

    Fix out-of-tree make check
    
    * test/lisp/custom-tests.el (custom-test-admin-cus-test): New const.
    (check-for-wrong-custom-types): Use it.
---
 test/lisp/custom-tests.el | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/test/lisp/custom-tests.el b/test/lisp/custom-tests.el
index d94527b..07f626f 100644
--- a/test/lisp/custom-tests.el
+++ b/test/lisp/custom-tests.el
@@ -147,9 +147,13 @@
                                (widget-apply field :value-to-internal 
origvalue)
                                "bar"))))))
 
+(defconst custom-test-admin-cus-test
+  (expand-file-name "admin/cus-test.el" source-directory))
+
 (ert-deftest check-for-wrong-custom-types ()
   :tags '(:expensive-test)
-  (load (concat installation-directory "admin/cus-test.el"))
+  (skip-unless (file-readable-p custom-test-admin-cus-test))
+  (load custom-test-admin-cus-test)
   (should (null (cus-test-opts t))))
 
 ;;; custom-tests.el ends here