Fix misc. linter issues (comments, variable naming, etc.)

We've accumulated a few linter issues around comments and a couple of
variable names.

While none of them is major, this patch cleans them up so it's easier to
go through the linter output, and we can start being more strict about
it.

test/t-03-queue_persistency/addtoqueue.go

@@ -4,6 +4,7 @@
 // Note that chasquid does NOT support this, we do it before starting up the
 // daemon for testing purposes only.
 //
+//go:build ignore
 // +build ignore
 
 package main