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

test/util/conngen/conngen.go

@@ -31,7 +31,6 @@ var (
 
 var (
 	host string
-	exit bool
 )
 
 func main() {
@@ -73,8 +72,13 @@ func main() {
 			time.Sleep(24 * time.Hour)
 		}
 	}
+
+	for _, c := range conns {
+		c.close()
+	}
 }
 
+// C represents a single connection.
 type C struct {
 	tr trace.Trace
 	n  net.Conn

test/util/coverhtml/coverhtml.go

@@ -90,6 +90,7 @@ func main() {
 	fmt.Printf("Total: %.1f\n", totals.TotalPercent())
 }
 
+// Totals is used to keep track of total counters.
 type Totals struct {
 	// Total statements.
 	total int
@@ -104,6 +105,7 @@ type Totals struct {
 	coveredF map[string]int
 }
 
+// Add the given profile to the total counters.
 func (t *Totals) Add(p *cover.Profile) {
 	for _, b := range p.Blocks {
 		t.total += b.NumStmt
@@ -115,10 +117,12 @@ func (t *Totals) Add(p *cover.Profile) {
 	}
 }
 
+// Percent covered for the given file.
 func (t *Totals) Percent(f string) float32 {
 	return float32(t.coveredF[f]) / float32(t.totalF[f]) * 100
 }
 
+// TotalPercent covered, across all files.
 func (t *Totals) TotalPercent() float32 {
 	return float32(t.covered) / float32(t.total) * 100
 }

test/util/loadgen/loadgen.go

@@ -126,7 +126,7 @@ func serial(id int) {
 	var count int64
 	start := time.Now()
 	for {
-		count += 1
+		count++
 		err := one()
 		if err != nil {
 			log.Fatalf("%v", err)

test/util/minidns/minidns.go

@@ -119,7 +119,11 @@ func (m *miniDNS) listenAndServeUDP(addr string) {
 			log.Fatalf("error packing reply: %v", err)
 		}
 
-		conn.WriteTo(rbuf, addr)
+		_, err = conn.WriteTo(rbuf, addr)
+		if err != nil {
+			log.Infof("%v/%-5d  error writing: %v",
+				addr, msg.ID, err)
+		}
 	}
 }
 
@@ -245,7 +249,7 @@ func (m *miniDNS) loadZones(f *os.File) {
 			continue
 		}
 
-		vs := regexp.MustCompile("\\s+").Split(line, 3)
+		vs := regexp.MustCompile(`\s+`).Split(line, 3)
 		if len(vs) != 3 {
 			log.Fatalf("line %d: invalid format", lineno)
 		}