e2e metrics: remove incorrect comment

The "should report resource usage through the resource metrics api" E2E test
calls getResourceMetrics, which calls GrabKubeletMetricsWithoutProxy.

test/e2e/framework/metrics/kubelet_metrics.go

@@ -68,7 +68,6 @@ func NewKubeletMetrics() KubeletMetrics {
 }
 
 // GrabKubeletMetricsWithoutProxy retrieve metrics from the kubelet on the given node using a simple GET over http.
-// Currently only used in integration tests.
 func GrabKubeletMetricsWithoutProxy(nodeName, path string) (KubeletMetrics, error) {
 	resp, err := http.Get(fmt.Sprintf("http://%s%s", nodeName, path))
 	if err != nil {