Sorry, I broke the build for stable/13

From: Rick Macklem <rick.macklem_at_gmail.com>
Date: Fri, 19 May 2023 21:53:30 UTC
Oops, an MFC I did to-day broke the build for
stable/13. I have reverted the commits, so I
think things should be ok now.

My mistake was to assume that a change in
a .h file within a #ifdef _KERNEL would not
affect a userland build. (It turns out that code
in libprocstat defines _KERNEL.)

I'll work on a fix, rick