Fix a spurious test failure

tests/test-ido-completing-read+.el

@@ -328,9 +328,10 @@ also accept a quoted list for the sake of convenience."
          :to-throw))
 
       (it "shouldn't allow C-j to select an ambiguous match"
-        ;; Make this a no-op to avoid end-of-buffer errors, which are
-        ;; irrelevant to this test.
-        (spy-on 'scroll-other-window)
+        ;; Make this a no-op to prevent spurious end-of-buffer errors
+        ;; when ido tries to create a help buffer in a noninteractive
+        ;; emacs.
+        (spy-on 'ido-completion-auto-help)
         (expect
          (with-simulated-input "b C-j C-j C-j"
            (ido-completing-read+