Update editor-integration/emacs/dune.el

Co-authored-by: Shon Feder <shon.feder@gmail.com>
Signed-off-by: arvidj <arvid.jakobsson@gmail.com>

Author: arvidj

editor-integration/emacs/dune.el

@@ -430,8 +430,8 @@ For customization purposes, use `dune-mode-hook'."
 (defun dune-find-dominating ()
   "Find dominating dune file."
   (interactive)
-  (if-let* ((dune-file (locate-dominating-file "." "dune"))
-            (dune-file (concat dune-file "dune")))
+  (if-let* ((dune-file-dir (locate-dominating-file "." "dune"))
+            (dune-file (concat dune-file-dir "dune")))
       (progn
         (xref-push-marker-stack)
         (find-file dune-file))