fix incorrect parameter passing

cmd/kubeadm/app/phases/kubeconfig/kubeconfig_test.go

@@ -177,7 +177,7 @@ func TestWriteKubeconfigToDisk(t *testing.T) {
 				err,
 			)
 		}
-		newFile, err := ioutil.ReadFile(configPath)
+		newFile, _ := ioutil.ReadFile(configPath)
 		if !bytes.Equal(newFile, rt.file) {
 			t.Errorf(
 				"failed WriteKubeconfigToDisk config write:\n\texpected: %s\n\t  actual: %s",