kern/56629: pfil(9) is at odds with reality

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         56629
>Category:       kern
>Synopsis:       pfil(9) is at odds with reality
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          doc-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jan 15 15:05:00 +0000 2022
>Originator:     Andreas Gustafsson
>Release:        NetBSD 9.2, -current
>Organization:
>Environment:
System: NetBSD
Architecture: x86_64
Machine: amd64
>Description:

The pfil(9) man page documents the functions pfil_head_register() and
pfil_head_unregister() which don't actually exist in the kernel.

Apparently they were replaced by something else in this commit:

Author: rmind <rmind%NetBSD.org@localhost>
Date:   Sat Jun 29 21:06:57 2013 +0000

    - Rewrite parts of pfil(9): use array to store hooks and thus be more cache
      friendly (there are only few hooks in the system).  Make the structures
      opaque and the interface more strict.
    - Remove PFIL_HOOKS option by making pfil(9) mandatory.

>How-To-Repeat:

>Fix: