TreeWalkJava7Test: Open TreeWalk in try-with-resource

Change-Id: I99a483c482b5395653b0d57b368ec1b5fdba450c
Signed-off-by: David Pursehouse <david.pursehouse@sonymobile.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/TreeWalkJava7Test.java

@@ -60,13 +60,14 @@ public class TreeWalkJava7Test extends RepositoryTestCase {
 		assertTrue(fs.supportsSymlinks());
 		writeTrashFile("target/data", "targetdata");
 		fs.createSymLink(new File(trash, "link"), "target");
-		TreeWalk tw = new TreeWalk(db);
-		tw.setRecursive(true);
-		tw.addTree(new FileTreeIterator(db));
-		assertTrue(tw.next());
-		assertEquals("link", tw.getPathString());
-		assertTrue(tw.next());
-		assertEquals("target/data", tw.getPathString());
-		assertFalse(tw.next());
+		try (TreeWalk tw = new TreeWalk(db)) {
+			tw.setRecursive(true);
+			tw.addTree(new FileTreeIterator(db));
+			assertTrue(tw.next());
+			assertEquals("link", tw.getPathString());
+			assertTrue(tw.next());
+			assertEquals("target/data", tw.getPathString());
+			assertFalse(tw.next());
+		}
 	}
 }