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

Author: pohly

logs/json/json_test.go

@@ -65,6 +65,7 @@ func TestZapLoggerInfo(t *testing.T) {
 		var buffer bytes.Buffer
 		writer := zapcore.AddSync(&buffer)
 		sampleInfoLogger, _ := NewJSONLogger(writer, nil, nil)
+		// nolint:logcheck // The linter cannot and doesn't need to check the key/value pairs.
 		sampleInfoLogger.Info(data.msg, data.keysValues...)
 		logStr := buffer.String()