kernel, sysctl(8): remove dead variable: tickadj

The global "tickadj" variable is a remnant of the old NTP adjustment
code we used in the kernel before the current timecounter subsystem
was imported from FreeBSD circa 2004 or 2005.

Fifteen years hence it is completely vestigial and we can remove it.
We probably should have removed it long ago but I guess it slipped
through the cracks.  FreeBSD removed it in 2002:

https://cgit.freebsd.org/src/commit/?id=e1d970f1811e5e1e9c912c032acdcec6521b2a6d

NetBSD and DragonflyBSD can probably remove it, too.

We export tickadj via the kern.clockrate sysctl(2), so update sysctl.2
and sysctl(8) accordingly.  Hypothetically this change could break
someone's sysctl(8) parsing script.  I don't think that's very likely.

ok mvs@

1 files changed, 4 insertions, 5 deletions

diff --git a/lib/libc/sys/sysctl.2 b/lib/libc/sys/sysctl.2
index d430659cde3..f11c226ca39 100644
--- a/lib/libc/sys/sysctl.2
+++ b/lib/libc/sys/sysctl.2
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: sysctl.2,v 1.42 2020/12/29 12:28:23 mglocker Exp $
+.\"	$OpenBSD: sysctl.2,v 1.43 2021/01/13 16:28:49 cheloha Exp $
 .\"
 .\" Copyright (c) 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -27,7 +27,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: December 29 2020 $
+.Dd $Mdocdate: January 13 2021 $
 .Dt SYSCTL 2
 .Os
 .Sh NAME
@@ -550,9 +550,8 @@ The scheduler exponential decay value.
 A
 .Vt struct clockinfo
 structure is returned.
-This structure contains the clock, statistics clock and profiling clock
-frequencies, the number of micro-seconds per hz tick, and the clock
-skew rate.
+This structure contains the hard clock, statistics clock and profiling clock
+frequencies, and the number of microseconds per hard clock tick.
 .It Dv KERN_CONSDEV Pq Va kern.consdev
 The console device.
 .It Dv KERN_CPTIME Pq Va kern.cp_time