tests: Don't print log messages on stdout

A parser of test results doesn't expect to see any extra messages.

PiperOrigin-RevId: 298966577

pkg/seccomp/seccomp_test.go

@@ -451,7 +451,7 @@ func TestRandom(t *testing.T) {
 		}
 	}
 
-	fmt.Printf("Testing filters: %v", syscallRules)
+	t.Logf("Testing filters: %v", syscallRules)
 	instrs, err := BuildProgram([]RuleSet{
 		RuleSet{
 			Rules:  syscallRules,

runsc/container/console_test.go

@@ -333,13 +333,13 @@ func TestJobControlSignalRootContainer(t *testing.T) {
 	// file. Writes after a certain point will block unless we drain the
 	// PTY, so we must continually copy from it.
 	//
-	// We log the output to stdout for debugabilitly, and also to a buffer,
+	// We log the output to stderr for debugabilitly, and also to a buffer,
 	// since we wait on particular output from bash below. We use a custom
 	// blockingBuffer which is thread-safe and also blocks on Read calls,
 	// which makes this a suitable Reader for WaitUntilRead.
 	ptyBuf := newBlockingBuffer()
 	tee := io.TeeReader(ptyMaster, ptyBuf)
-	go io.Copy(os.Stdout, tee)
+	go io.Copy(os.Stderr, tee)
 
 	// Start the container.
 	if err := c.Start(conf); err != nil {