unit修改接口bug修复

cqb-paper/src/main/java/com/qmth/cqb/paper/service/PaperDetailUnitService.java

@@ -90,8 +90,9 @@ public class PaperDetailUnitService {
             oldPdu.setScore(pduExp.getScore());
         }
         // 同时要跟新小题里面的Qustion对象
+        oldPdu = paperDetailUnitRepo.save(oldPdu);
         paperService.formatPaper(oldPdu.getPaper());
-        return paperDetailUnitRepo.save(oldPdu);
+        return oldPdu;
     }
 
     /**