8362855: Test java/net/ipv6tests/TcpTest.java should report SkippedException when there no ia4addr or ia6addr

Backport-of: 8fcbb110e9941af5fe162c6affff36e0bf652bda

Author: SendaoYan

test/jdk/java/net/ipv6tests/TcpTest.java

@@ -31,13 +31,16 @@
  * @library /test/lib
  * @build jdk.test.lib.NetworkConfiguration
  *        jdk.test.lib.Platform
+ *        jtreg.SkippedException
  * @run main TcpTest -d
  */
 
 import java.net.*;
 import java.io.*;
 import java.util.concurrent.TimeUnit;
 
+import jtreg.SkippedException;
+
 public class TcpTest extends Tests {
     static ServerSocket server, server1, server2;
     static Socket c1, c2, c3, s1, s2, s3;
@@ -62,12 +65,10 @@ public class TcpTest extends Tests {
     public static void main (String[] args) throws Exception {
         checkDebug(args);
         if (ia4addr == null) {
-            System.out.println ("No IPV4 addresses: exiting test");
-            return;
+            throw new SkippedException("No IPV4 addresses: exiting test");
         }
         if (ia6addr == null) {
-            System.out.println ("No IPV6 addresses: exiting test");
-            return;
+            throw new SkippedException("No IPV6 addresses: exiting test");
         }
         dprintln ("Local Addresses");
         dprintln (ia4addr.toString());