remove registerSql from taos_stmt_prepare and taos_free_result

src/client/src/tscPrepare.c

@@ -1567,8 +1567,6 @@ int taos_stmt_prepare(TAOS_STMT* stmt, const char* sql, unsigned long length) {
   pRes->qId = 0;
   pRes->numOfRows = 1;
 
-  registerSqlObj(pSql);
-
   strtolower(pSql->sqlstr, sql);
   tscDebugL("0x%"PRIx64" SQL: %s", pSql->self, pSql->sqlstr);
 
@@ -1817,7 +1815,7 @@ int taos_stmt_close(TAOS_STMT* stmt) {
   }
 
   if (RID_VALID(pStmt->pSql->self)) {
-    taosReleaseRef(tscObjRef, pStmt->pSql->self);
+    taos_free_result(pStmt->pSql);
   } else {
     tscFreeSqlObj(pStmt->pSql);
   }