routing: make sure StatusInitiated is notified when creating payments

This commit fixes `InitPayment` method to make sure the subscribers get
notified when new payments are created.

routing/control_tower.go

@@ -181,12 +181,29 @@ func NewControlTower(db *channeldb.PaymentControl) ControlTower {
 
 // InitPayment checks or records the given PaymentCreationInfo with the DB,
 // making sure it does not already exist as an in-flight payment. Then this
-// method returns successfully, the payment is guaranteed to be in the InFlight
-// state.
+// method returns successfully, the payment is guaranteed to be in the
+// Initiated state.
 func (p *controlTower) InitPayment(paymentHash lntypes.Hash,
 	info *channeldb.PaymentCreationInfo) error {
 
-	return p.db.InitPayment(paymentHash, info)
+	err := p.db.InitPayment(paymentHash, info)
+	if err != nil {
+		return err
+	}
+
+	// Take lock before querying the db to prevent missing or duplicating
+	// an update.
+	p.paymentsMtx.Lock(paymentHash)
+	defer p.paymentsMtx.Unlock(paymentHash)
+
+	payment, err := p.db.FetchPayment(paymentHash)
+	if err != nil {
+		return err
+	}
+
+	p.notifySubscribers(paymentHash, payment)
+
+	return nil
 }
 
 // DeleteFailedAttempts deletes all failed htlcs if the payment was