bug fix in the channel tear down

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@15457 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/test/java/hudson/FilePathTest.java

@@ -69,8 +69,7 @@ public class FilePathTest extends TestCase {
 
     @Override
     protected void tearDown() throws Exception {
-        french.close();
-        british.close();
+        french.close(); // this will automatically initiate the close on the other channel, too.
         french.join();
         british.join();
         executors.shutdown();