nadvice.el: Avoid exponential blow up in interactive-form recursion
* lisp/emacs-lisp/nadvice.el (advice--interactive-form): Sink the call
to `commandp` into the autoloaded function case since it's redundant in
the other branch.
(advice--make-interactive-form): Take just the interactive forms rather
than the actual functions as arguments.
(oclosure-interactive-form): Use `advice--interactive-form` rather than
`commandp` since we'd call `advice--interactive-form` afterwards anyway.