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**:

staging/src/k8s.io/apiserver/pkg/endpoints/metrics/metrics.go

@@ -215,7 +215,7 @@ func InstrumentRouteFunc(verb, resource, subresource, scope string, routeFunc re
 
 		routeFunc(request, response)
 
-		MonitorRequest(request.Request, verb, resource, subresource, scope, delegate.Header().Get("Content-Type"), delegate.Status(), delegate.ContentLength(), time.Now().Sub(now))
+		MonitorRequest(request.Request, verb, resource, subresource, scope, delegate.Header().Get("Content-Type"), delegate.Status(), delegate.ContentLength(), time.Since(now))
 	})
 }
 
@@ -237,7 +237,7 @@ func InstrumentHandlerFunc(verb, resource, subresource, scope string, handler ht
 
 		handler(w, req)
 
-		MonitorRequest(req, verb, resource, subresource, scope, delegate.Header().Get("Content-Type"), delegate.Status(), delegate.ContentLength(), time.Now().Sub(now))
+		MonitorRequest(req, verb, resource, subresource, scope, delegate.Header().Get("Content-Type"), delegate.Status(), delegate.ContentLength(), time.Since(now))
 	}
 }
 

staging/src/k8s.io/client-go/plugin/pkg/client/auth/openstack/openstack.go

@@ -95,7 +95,7 @@ func (c *cachedGetter) Token() (string, error) {
 
 	var err error
 	// no token or exceeds the TTL
-	if c.token == "" || time.Now().Sub(c.born) > c.ttl {
+	if c.token == "" || time.Since(c.born) > c.ttl {
 		c.token, err = c.tokenGetter.Token()
 		if err != nil {
 			return "", fmt.Errorf("failed to get token: %s", err)