DiffAlgorithms: Fix warnings about variable hiding

Local variables/parameters named 'db' and 'cmp' were hiding class
member variables of the same name.

Change-Id: I98b770587aaf73744a93e6a3ee33d131a9fa91e9
Signed-off-by: David Pursehouse <david.pursehouse@sonymobile.com>

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/debug/DiffAlgorithms.java

@@ -155,16 +155,16 @@ class DiffAlgorithms extends TextBuiltin {
 			else
 				rb.findGitDir(dir);
 
-			Repository db = rb.build();
+			Repository repo = rb.build();
 			try {
-				run(db);
+				run(repo);
 			} finally {
-				db.close();
+				repo.close();
 			}
 		}
 	}
 
-	private void run(Repository db) throws Exception {
+	private void run(Repository repo) throws Exception {
 		List<Test> all = init();
 
 		long files = 0;
@@ -173,14 +173,14 @@ class DiffAlgorithms extends TextBuiltin {
 		int maxN = 0;
 
 		AbbreviatedObjectId startId;
-		try (ObjectReader or = db.newObjectReader();
+		try (ObjectReader or = repo.newObjectReader();
 			RevWalk rw = new RevWalk(or)) {
 			final MutableObjectId id = new MutableObjectId();
 			TreeWalk tw = new TreeWalk(or);
 			tw.setFilter(TreeFilter.ANY_DIFF);
 			tw.setRecursive(true);
 
-			ObjectId start = db.resolve(Constants.HEAD);
+			ObjectId start = repo.resolve(Constants.HEAD);
 			startId = or.abbreviate(start);
 			rw.markStart(rw.parseCommit(start));
 			for (;;) {
@@ -235,14 +235,15 @@ class DiffAlgorithms extends TextBuiltin {
 
 		Collections.sort(all, new Comparator<Test>() {
 			public int compare(Test a, Test b) {
-				int cmp = Long.signum(a.runningTimeNanos - b.runningTimeNanos);
-				if (cmp == 0)
-					cmp = a.algorithm.name.compareTo(b.algorithm.name);
-				return cmp;
+				int result = Long.signum(a.runningTimeNanos - b.runningTimeNanos);
+				if (result == 0) {
+					result = a.algorithm.name.compareTo(b.algorithm.name);
+				}
+				return result;
 			}
 		});
 
-		File directory = db.getDirectory();
+		File directory = repo.getDirectory();
 		if (directory != null) {
 			String name = directory.getName();
 			File parent = directory.getParentFile();