Change `indexState` to static method

The `indexState` method is no longer referring to any
member variables from the class, so it can be made static.

Bug: 436200
Change-Id: I013316de5c373417ea758ca6e17da29209fead53
Signed-off-by: Chris Price <chris@puppetlabs.com>

org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/RepositoryTestCase.java

@@ -204,7 +204,7 @@ public abstract class RepositoryTestCase extends LocalDiskRepositoryTestCase {
 	 * @throws IllegalStateException
 	 * @throws IOException
 	 */
-	public String indexState(Repository repo, int includedOptions)
+	public static String indexState(Repository repo, int includedOptions)
 			throws IllegalStateException, IOException {
 		DirCache dc = repo.readDirCache();
 		StringBuilder sb = new StringBuilder();