fix lock value copy bug

exporter.go

@@ -45,11 +45,12 @@ func NewExporter(accountAddress []string) (*Exporter, error) {
 // Account represents a helium account
 type Account struct {
 	Address      string
-	UpdateLock   sync.Mutex
 	LastUpdate   time.Time
 	RewardsTotal map[string]int
 	Tx           AccountTx
 	Hotspots     map[string]Hotspot
+
+	UpdateLock *sync.Mutex
 }
 
 func NewAccount(address string) Account {
@@ -67,6 +68,8 @@ func NewAccount(address string) Account {
 			WithdrawalTotal: 0,
 		},
 		Hotspots: map[string]Hotspot{},
+
+		UpdateLock: &sync.Mutex{},
 	}
 }
 
@@ -78,9 +81,10 @@ type AccountTx struct {
 // Hotspot represents a hotspot
 type Hotspot struct {
 	Address      string
-	UpdateLock   sync.Mutex
 	LastUpdate   time.Time
 	RewardsTotal map[string]int
+
+	UpdateLock *sync.Mutex
 }
 
 func NewHotspot(address string) Hotspot {
@@ -93,6 +97,8 @@ func NewHotspot(address string) Hotspot {
 			"poc_challengees": 0,
 			"poc_witnesses":   0,
 		},
+
+		UpdateLock: &sync.Mutex{},
 	}
 }