fix:解决集成测试osEventFlagsGet传NULL时应该返回0

主干不存在该问题，已解决.

集成测试osEventFlagsGet传NULL时应该返回0

修改集成测试osEventFlagsGet传NULL时返回osFlagsErrorParameter,CMSIS-RTOS2返回值为0

Close #I48FKQ

Signed-off-by: dong-yiqun <dongyiqun@huawei.com>

kal/cmsis/cmsis_liteos2.c

@@ -891,7 +891,7 @@ uint32_t osEventFlagsGet(osEventFlagsId_t ef_id)
     uint32_t rflags;
 
     if (pstEventCB == NULL) {
-        return (uint32_t)osFlagsErrorParameter;
+        return 0;
     }
 
     uwIntSave = LOS_IntLock();