makesyscalls.lua: Make more luaish

[imp]

Summary

x["y"] can be written as x.y, which looks better and is a more typical
lua idiom.

Sponsored by: Netflix

Test Plan

cd sys/kern
make sysent
git diff

should show nothing (or only changes to sys/tools/makesyscalls.lua)

[kevans]

Seems reasonable to me; I have two requests that aren't really related to this change, though it'd be nice if you could include them or just smack them in a follow-up so that I don't conflict with your work. They're luacheck-noted issues (unknown global line and unused arg comment)

sys/tools/makesyscalls.lua

525

Can you make this local line = ... while you're at it, please?

1055

and remove the comment argument here, please

[imp]

Two things: 1. Mind if I do that as a followup commit? 2. Where is this luacheck obtained?

[kevans]

In D39709#903653, @imp wrote:

Two things: 1. Mind if I do that as a followup commit? 2. Where is this luacheck obtained?

Yeah, feel free!

iuacheck is available in ports, devel/lua-luacheck, or as the lua54-luacheck pkg. I try to keep our lua scripts luacheck clean, it has just about the right level of nagging about poor form.