Remove $FreeBSD$: one-line .c comment pattern

Remove /^/[*/]\s*\$FreeBSD\$.*\n/

Fix typos.

MFC after: 2 weeks
Sponsored by: Klara, Inc

Add libxo(3) support to sesutil(8)

This is useful to simplify parsing "sesutil map"

Submitted by: nikita.kozlov@blade-group.com
MFC after: 3 weeks
Relnotes: yes
Sponsored by: blade

Directly print the extra status instead of filling a buffer
then printing it.

This prepares the code to make it libxo friendly

Reviewed by: manu, Nikita Kozlov (nikita elyzion.net)
MFC after: 2 weeks
Sponsored by: Gandi.net

Do not use sprintf(3) when not needed, while here,
prefer snprintf(3) over sprintf(3)

Cleanup headers

Found by: include-what-you-use

sesutil: Add extra information specific to some SES devices to sesutil map

Rework stat2ascii preparing a buffer of what could be printed. This prevent the
risk of overflowing a static buffer.

Do not print those informations anymore in the "status" but into a new
"extra status" only printed if there are actually extra things to print.

Now add those extra informations:

* Thermal sensor temperature
* Cooling devices speed
* Voltage sensors, current consumption

Tested by: AllanJude
Sponsored by: Gandi.net
Differential Revision: https://reviews.freebsd.org/D4520

sesutil: fix map not printing the status of the LED device in an array

Sponsored by: Gandi.net

Improve and expand sesutil(8)

- Return an error if no matching device is found when the locate command is run
- Enhance the locate command to be able to address drive bays with no disk, or where the SES controller has not made the mapping to the device name
- Added the fault command, similar to locate, but a different SES property. On some of my controllers locate blinks the activity light, others the fault light. The fault command keeps the fault light on constant.
- Improve the usage() output and use it everywhere
- Added the map command, displays all elements connected to each (or the specified) ses(4) controller
- Added the status command, returns the overall status of the ses(4) controller

Reviewed by: wblock (man page, earlier version)
Approved by: bapt (mentor)
MFC after: 3 weeks
Relnotes: yes
Sponsored by: ScaleEngine Inc.
Differential Revision: https://reviews.freebsd.org/D3580