libct/int/TestExecInTTY: repeat the test 300 times

This is to increase the chance to hit the recently fixed race.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

libcontainer/integration/execin_test.go

@@ -291,13 +291,16 @@ func TestExecInTTY(t *testing.T) {
 		Args: []string{"ps"},
 		Env:  standardEnvironment,
 	}
+
+	// Repeat to increase chances to catch a race; see
+	// https://github.com/opencontainers/runc/issues/2425.
+	for i := 0; i < 300; i++ {
 		parent, child, err := utils.NewSockPair("console")
 		if err != nil {
 			ok(t, err)
 		}
-	defer parent.Close()
-	defer child.Close()
 		ps.ConsoleSocket = child
+
 		done := make(chan (error))
 		go func() {
 			f, err := utils.RecvFd(parent)
@@ -315,15 +318,20 @@ func TestExecInTTY(t *testing.T) {
 			_, _ = io.Copy(&stdout, c)
 			done <- nil
 		}()
+
 		err = container.Run(ps)
 		ok(t, err)
+
 		select {
 		case <-time.After(5 * time.Second):
 			t.Fatal("Waiting for copy timed out")
 		case err := <-done:
 			ok(t, err)
 		}
+
 		waitProcess(ps, t)
+		parent.Close()
+		child.Close()
 
 		out := stdout.String()
 		if !strings.Contains(out, "cat") || !strings.Contains(out, "ps") {
@@ -332,6 +340,7 @@ func TestExecInTTY(t *testing.T) {
 		if strings.Contains(out, "\r") {
 			t.Fatalf("unexpected carriage-return in output %q", out)
 		}
+	}
 }
 
 func TestExecInEnvironment(t *testing.T) {