sysstat: upgrade 12.6.0 -> 12.6.1

Changelog:
==========
* Fix possible overflow in sa_common.c (GHSL-2022-074).
* sa_conv.c: Make size of statistics structures from older sysstat
  versions immutable.
* Declare sadc dependency on libsyscom.a.
* Fix gcc v11.2 warnings.
* Various cosmetic fixes.
* sar: Remove `-I int_list` from man-page and help.
* Consolidate systemctl commands in README file.
* Remove whitespace characters at the end of lines.

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>