ReflogTest: Open Git instances in try-with-resource

Change-Id: I950b6f16148cfe11de729b04904f88d6e4c28b9a
Signed-off-by: David Pursehouse <david.pursehouse@sonymobile.com>

org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/ReflogTest.java

@@ -57,15 +57,17 @@ public class ReflogTest extends CLIRepositoryTestCase {
 
 	@Test
 	public void testSingleCommit() throws Exception {
-		new Git(db).commit().setMessage("initial commit").call();
+		try (Git git = new Git(db)) {
+			git.commit().setMessage("initial commit").call();
 
 			assertEquals("6fd41be HEAD@{0}: commit (initial): initial commit",
 					execute("git reflog")[0]);
 		}
+	}
 
 	@Test
 	public void testBranch() throws Exception {
-		Git git = new Git(db);
+		try (Git git = new Git(db)) {
 			git.commit().setMessage("first commit").call();
 			git.checkout().setCreateBranch(true).setName("side").call();
 			writeTrashFile("file", "side content");
@@ -78,3 +80,4 @@ public class ReflogTest extends CLIRepositoryTestCase {
 					"" }, execute("git reflog refs/heads/side"));
 		}
 	}
+}