usr.bin: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

systat: Chase 70ea484e3ec5, removing vdev_cache

As of 70ea484e3ec5 vdev_cache has been removed. Stop reporting on it.
Without this systat reports:

sysctl(kstat.zfs.misc.vdev_cache_stats.misses...) failed:
No such file or directory

Reviewed by: mav
Differential Revision: https://reviews.freebsd.org/D40742

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

Clean up copyright messages.

Reported by: Yoshihiro Ota
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D29354

Patch systat -zarc to display cumulative rate and round down large numbers by SI units

PR: 237664
Submitted by: ota@j.email.ne.jp
MFC after: 2 weeks

systat -zarc to display disk activities like -vm

PR: 213310
Submitted by: ota
MFH: 4 weeks
Differential Revision: https://reviews.freebsd.org/D18726

Fix printing of 64-bit counters on 32-bit ppc platforms.

Several statistic counters are uint64_t values and are printed by systat
using %lu. This results in displaying wrong numbers. Use PRIu64 instead.
While there, print variables of size_t using %zd.

MFC after:i 3 days
Differential Revision: https://reviews.freebsd.org/D17838

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

Add support to systat to display zfs arc cache status/info

PR: 195460
Submitted by: ota