lnwallet: make BlockChainIO.GetUTXO take cancel chan

Use quit channels as cancel chan for call to GetUTXO.

routing/notifications_test.go

@@ -181,7 +181,8 @@ func (m *mockChain) addUtxo(op wire.OutPoint, out *wire.TxOut) {
 	m.utxos[op] = *out
 	m.Unlock()
 }
-func (m *mockChain) GetUtxo(op *wire.OutPoint, _ []byte, _ uint32) (*wire.TxOut, error) {
+func (m *mockChain) GetUtxo(op *wire.OutPoint, _ []byte, _ uint32,
+	_ <-chan struct{}) (*wire.TxOut, error) {
 	m.RLock()
 	defer m.RUnlock()
 

routing/router.go

@@ -1113,6 +1113,7 @@ func (r *ChannelRouter) processUpdate(msg interface{}) error {
 		// been closed so we'll ignore it.
 		chanUtxo, err := r.cfg.Chain.GetUtxo(
 			fundingPoint, fundingPkScript, channelID.BlockHeight,
+			r.quit,
 		)
 		if err != nil {
 			r.rejectMtx.Lock()