重构代码；修改mapId为-1的exam_status表，表示考试状态

endian11

2020-08-13 a927c72c0f06ef5bd771e5ae00bc35155c271762

 app/src/main/java/safeluck/drive/evaluation/DB/exam_status/ExamStatusViewModel.java

@@ -58,4 +58,9 @@
    public void updateItemExamResult(int i, int map_id) {
        examStatusWorkRepo.updateItemResult(i,map_id);
    }

    public void deleteAll() {

        examStatusWorkRepo.deleteAll();
    }
}