Merge pull request #59727 from wgliang/master.time

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

should use time.Since instead of time.Now().Sub

**What this PR does / why we need it**:
should use time.Since instead of time.Now().Sub

**Special notes for your reviewer**:

test/images/liveness/server.go

@@ -29,11 +29,11 @@ func main() {
 	started := time.Now()
 	http.HandleFunc("/started", func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(200)
-		data := (time.Now().Sub(started)).String()
+		data := (time.Since(started)).String()
 		w.Write([]byte(data))
 	})
 	http.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
-		duration := time.Now().Sub(started)
+		duration := time.Since(started)
 		if duration.Seconds() > 10 {
 			w.WriteHeader(500)
 			w.Write([]byte(fmt.Sprintf("error: %v", duration.Seconds())))

test/images/resource-consumer/consume-cpu/consume_cpu.go

@@ -45,7 +45,7 @@ func main() {
 	duration := time.Duration(*durationSec) * time.Second
 	start := time.Now()
 	first := systemstat.GetProcCPUSample()
-	for time.Now().Sub(start) < duration {
+	for time.Since(start) < duration {
 		cpu := systemstat.GetProcCPUAverage(first, systemstat.GetProcCPUSample(), systemstat.GetUptime().Uptime)
 		if cpu.TotalPct < millicoresPct {
 			doSomething()