Eliminate inappropriate evaluation in macro

The override argument to ido-ubiquitous-with-override was being
evaluated at macro-expansion time instead of runtime.

ido-ubiquitous.el

@@ -338,8 +338,7 @@ literal symbol, it must be quoted.
 
 See `ido-ubiquitous-command-overrides' for valid override types."
   ;; Eval override
-  (setq override (ignore-errors (eval override)))
-  `(let ((ido-ubiquitous-next-override ',override))
+  `(let ((ido-ubiquitous-next-override ,override))
      ,@body))
 (put 'ido-ubiquitous-with-override 'lisp-indent-function
      (get 'prog1 'lisp-indent-function))