blame: unbreak "diff -U 0".

The commit 604c86d changed the
original "diff -u0" to "diff -u -U 0" for portability.

A big mistake without proper testing.

The form "diff -u -U 0" shows the default 3-line contexts,
because -u and -U 0 contradicts with each other; "diff -U 0" (or
its longhand "diff --unified=0") is what we meant.

Signed-off-by: Junio C Hamano <junkio@cox.net>

blame.c

@@ -92,7 +92,7 @@ static struct patch *get_patch(struct commit *commit, struct commit *other)
 		die("write failed: %s", strerror(errno));
 	close(fd);
 
-	sprintf(diff_cmd, "diff -u -U 0 %s %s", tmp_path1, tmp_path2);
+	sprintf(diff_cmd, "diff -U 0 %s %s", tmp_path1, tmp_path2);
 	fin = popen(diff_cmd, "r");
 	if (!fin)
 		die("popen failed: %s", strerror(errno));
@@ -234,7 +234,7 @@ static void print_patch(struct patch *p)
 	}
 }
 
-#if 0
+#if DEBUG
 /* For debugging only */
 static void print_map(struct commit *cmit, struct commit *other)
 {