enhance and fix log calls

Some of these changes are cosmetic (repeatedly calling klog.V instead of
reusing the result), others address real issues:

- Logging a message only above a certain verbosity threshold without
  recording that verbosity level (if klog.V().Enabled() { klog.Info... }):
  this matters when using a logging backend which records the verbosity
  level.

- Passing a format string with parameters to a logging function that
  doesn't do string formatting.

All of these locations where found by the enhanced logcheck tool from
kubernetes/klog#297.

In some cases it reports false positives, but those can be suppressed with
source code comments.

Kubernetes-commit: edffc700a43e610f641907290a5152ca593bad79

gce/gce_loadbalancer_internal.go

@@ -31,7 +31,7 @@ import (
 	"github.com/GoogleCloudPlatform/k8s-cloud-provider/pkg/cloud/meta"
 	"github.com/google/go-cmp/cmp"
 	compute "google.golang.org/api/compute/v1"
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/sets"
 	cloudprovider "k8s.io/cloud-provider"
@@ -202,9 +202,9 @@ func (g *Cloud) ensureInternalLoadBalancer(clusterName, clusterID string, svc *v
 		// Delete existing forwarding rule before making changes to the backend service. For example - changing protocol
 		// of backend service without first deleting forwarding rule will throw an error since the linked forwarding
 		// rule would show the old protocol.
-		if klog.V(2).Enabled() {
+		if klogV := klog.V(2); klogV.Enabled() {
 			frDiff := cmp.Diff(existingFwdRule, newFwdRule)
-			klog.V(2).Infof("ensureInternalLoadBalancer(%v): forwarding rule changed - Existing - %+v\n, New - %+v\n, Diff(-existing, +new) - %s\n. Deleting existing forwarding rule.", loadBalancerName, existingFwdRule, newFwdRule, frDiff)
+			klogV.Infof("ensureInternalLoadBalancer(%v): forwarding rule changed - Existing - %+v\n, New - %+v\n, Diff(-existing, +new) - %s\n. Deleting existing forwarding rule.", loadBalancerName, existingFwdRule, newFwdRule, frDiff)
 		}
 		if err = ignoreNotFound(g.DeleteRegionForwardingRule(loadBalancerName, g.region)); err != nil {
 			return nil, err