make go vet happy

Address `non-constant format string in call` check:
https://github.com/golang/go/issues/60529

Signed-off-by: hagen1778 <roman@victoriametrics.com>
(cherry picked from commit febba3971b)

app/vmalert/datasource/vm_prom_api_timing_test.go

@@ -13,7 +13,7 @@ func BenchmarkMetrics(b *testing.B) {
 
 	var pi promInstant
 	if err := pi.Unmarshal(payload); err != nil {
-		b.Fatalf(err.Error())
+		b.Fatal(err.Error())
 	}
 	b.Run("Instant", func(b *testing.B) {
 		for i := 0; i < b.N; i++ {

app/vmselect/main.go

@@ -194,7 +194,7 @@ func requestHandler(w http.ResponseWriter, r *http.Request) bool {
 	startTime := time.Now()
 	defer requestDuration.UpdateDuration(startTime)
 	tracerEnabled := httputils.GetBool(r, "trace")
-	qt := querytracer.New(tracerEnabled, r.URL.Path)
+	qt := querytracer.New(tracerEnabled, "%s", r.URL.Path)
 
 	// Limit the number of concurrent queries.
 	select {

lib/querytracer/tracer_test.go

@@ -1,7 +1,6 @@
 package querytracer
 
 import (
-	"fmt"
 	"regexp"
 	"sync"
 	"testing"
@@ -153,11 +152,11 @@ func TestTraceConcurrent(t *testing.T) {
 	childLocal.Done()
 	var wg sync.WaitGroup
 	for i := 0; i < 3; i++ {
-		child := qt.NewChild(fmt.Sprintf("child %d", i))
+		child := qt.NewChild("child %d", i)
 		wg.Add(1)
 		go func() {
 			for j := 0; j < 100; j++ {
-				child.Printf(fmt.Sprintf("message %d", j))
+				child.Printf("message %d", j)
 			}
 			wg.Done()
 		}()