e2e: suppress progress messages for custom progress reporter

The custom progress reporter gets invoked via ginkgo.ReportAfterEach after each
test. The problem was that the e2e framework unconditionally enables Ginkgo's
-progress output which shows execution of all nodes, including this
ReportAfterEach. The effect were over 1000 lines of useless output at the start
of a test run while skipping disabled tests.

The solution is to tell Ginkgo that the ReportAfterEach isn't meant to be
reported.

test/e2e/e2e_test.go

@@ -141,7 +141,7 @@ func TestE2E(t *testing.T) {
 
 var _ = ginkgo.ReportAfterEach(func(report ginkgo.SpecReport) {
 	progressReporter.ProcessSpecReport(report)
-})
+}, ginkgo.SuppressProgressReporting)
 
 var _ = ginkgo.ReportAfterSuite("Kubernetes e2e suite report", func(report ginkgo.Report) {
 	var err error