修复一个内存泄漏问题

（cherry picked commit from <gitee.com//opengauss/openGauss-server/commit/caefe8e180c6d669d9b24ec99bb57aaf3e663f83>

src/common/backend/utils/error/elog.cpp

@@ -6042,6 +6042,8 @@ void pushErrorData(ErrorData *edata)
             errorDataArea->sqlErrorDataList = lappend(errorDataArea->sqlErrorDataList, dolphinErrorData);
             errorDataArea->current_edata_count++;
             errorDataArea->current_edata_count_by_level[errorLevelToDolphin(edata->elevel)]++;
+            pfree_ext(class_origin);
+            pfree_ext(subclass_origin);
         }
     }
     MemoryContextSwitchTo(oldcontext);