revision --boundary: fix stupid typo

Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/revision.c b/revision.c
index 35a1711..f48d7f7 100644
--- a/revision.c
+++ b/revision.c
@@ -1247,7 +1247,7 @@
 				objects[j] = objects[i];
 			j++;
 		}
-		for (i = j; j < nr; j++)
+		for (i = j; i < nr; i++)
 			objects[i].item = NULL;
 		array->nr = j;
 	}