Improve friendlyness of the command line by accepting the percent brightness
in both format: with or without a trailing '%'
Reviewed by: manu
Differential Revision: https://reviews.freebsd.org/D26692
This tool is used to configure registered backlights.
It can incr/decr (default to 10%) or accept a percentage value directly.
Reviewed by: manpages (gbe@)
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26251