Remove useless var from base_param (#13603)

Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

internal/util/paramtable/base_param.go

@@ -21,12 +21,12 @@ import (
 
 // Params is a package scoped variable of type BaseParamTable.
 var Params BaseParamTable
-var once sync.Once
 
 // BaseParamTable is a derived struct of BaseTable. It achieves Composition by
 // embedding BaseTable. It is used to quickly and easily access the system configuration.
 type BaseParamTable struct {
 	BaseTable
+	once sync.Once
 
 	// --- ETCD ---
 	EtcdEndpoints []string
@@ -37,14 +37,12 @@ type BaseParamTable struct {
 	UseEmbedEtcd   bool
 	EtcdConfigPath string
 	EtcdDataDir    string
-
-	initOnce sync.Once
 }
 
 // Init is an override method of BaseTable's Init. It mainly calls the
 // Init of BaseTable and do some other initialization.
 func (p *BaseParamTable) Init() {
-	p.initOnce.Do(func() {
+	p.once.Do(func() {
 		p.BaseTable.Init()
 		p.LoadCfgToMemory()
 	})