How make vc-diff and vc-revert-buffer NOT ask to save files but do it automatically?

[Christian Seberino]

I tried wrappers for vc-diff and vc-revert-buffer like the ones below
to automatically
take care of saving the buffer and NOT ask me if I want to save the
buffer.

   (defun cs-vc-diff() (interactive)
      (vc-diff "yes"))
 
   (defun cs-vc-revert-buffer() (interactive)
      (save-buffer)
      (vc-revert-buffer "yes"))

These did not work but instead I got an error message about the "wrong
number
of arguments" and other junk.

How fix?

any help would be greatly appreaciated

Chris