pdkill(2), pdgetpid(2): return EBADF if the file type is not procdesc
For pdwait(2) and pddupfd(2), the returned error is kept EINVAL.
PR: 297293
Reviewed by: lwhsu, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D58666