ReceivePackAdvertiseRefsHookTest: Don't close repositories in teardown

The repositories get added to the "toClose" set by createBareRepository,
and are then closed in the superclass's tearDown method.

Explicitly closing them in this test class's teardown causes the use
count to go negative when subsequently closed again by the superclass.

Change-Id: Idcbb16b4cf4bf0640d7e4ac15d1926d8a27c1251
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/ReceivePackAdvertiseRefsHookTest.java

@@ -128,16 +128,6 @@ public class ReceivePackAdvertiseRefsHookTest extends LocalDiskRepositoryTestCas
 		d.update(R_PRIVATE, P);
 	}
 
-	@Override
-	@After
-	public void tearDown() throws Exception {
-		if (src != null)
-			src.close();
-		if (dst != null)
-			dst.close();
-		super.tearDown();
-	}
-
 	@Test
 	public void testFilterHidesPrivate() throws Exception {
 		Map<String, Ref> refs;