Make it const everywhere.

14 jobs for master in 9 minutes and 36 seconds (queued for 17 seconds)
Status Job ID Name Coverage
  Build
passed #31986
FreeBSD
jsdoor-freebsd

00:04:02

passed #31987
Linux
jsdoor-linux

00:06:41

passed #31989
FreeBSD
jsdoor-windows

00:01:54

passed #31981
FreeBSD
sbbs-freebsd

00:05:33

passed #31976
Linux
sbbs-linux

00:09:31

passed #31979
Windows
sbbs-windows

00:05:45

passed #31988
FreeBSD
sexpots-freebsd

00:00:10

passed #31977
Linux
sexpots-linux

00:00:21

passed #31980
Windows
sexpots-windows

00:00:29

passed #31984
FreeBSD
syncdraw-freebsd

00:00:23

passed #31985
Linux
syncdraw-linux

00:01:03

passed #31982
FreeBSD
syncterm-freebsd

00:01:01

passed #31978
Linux
syncterm-linux

00:02:52

passed #31983
FreeBSD
syncterm-windows

00:01:45