bug#41250: 28.0.50; Dired displays unconditionally ls-switches on modeline

[Drew Adams]

> > nil - to get the current behavior
> > `as-is' - show the full switches
> > an integer - show first N chars of switches
> > a function - show whatever it returns, when
> >              passed `dired-actual-switches'
> 
> Instead of `as-is' a simpler value could be just `t'.

Simpler how?  Because it's self-evaluating? :as-is