BundleWriterTest: Open RevWalk in try-with-resource

Change-Id: Ie25770a73b19d6522bad9fdc0966f48370f96265
Signed-off-by: David Pursehouse <david.pursehouse@sonymobile.com>

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

@@ -126,8 +126,9 @@ public class BundleWriterTest extends SampleDataRepositoryTestCase {
 		assertNull(newRepo.resolve("refs/heads/a"));
 
 		// Next an incremental bundle
+		try (RevWalk rw = new RevWalk(db)) {
 			bundle = makeBundle("refs/heads/cc", db.resolve("c").name(),
-				new RevWalk(db).parseCommit(db.resolve("a").toObjectId()));
+					rw.parseCommit(db.resolve("a").toObjectId()));
 			fetchResult = fetchFromBundle(newRepo, bundle);
 			advertisedRef = fetchResult.getAdvertisedRef("refs/heads/cc");
 			assertEquals(db.resolve("c").name(), advertisedRef.getObjectId().name());
@@ -146,6 +147,7 @@ public class BundleWriterTest extends SampleDataRepositoryTestCase {
 						.indexOf(db.resolve("refs/heads/a").name()) >= 0);
 			}
 		}
+	}
 
 	@Test
 	public void testAbortWrite() throws Exception {