htlcswitch: thread through packet's inbound wire records

For calculating the available auxiliary bandwidth of a channel, we need
access to the inbound custom wire records of the HTLC packet, which
might contain auxiliary information about the worth of the HTLC packet
apart from the BTC value being transported.

htlcswitch/switch.go

@@ -917,6 +917,7 @@ func (s *Switch) getLocalLink(pkt *htlcPacket, htlc *lnwire.UpdateAddHTLC) (
 	currentHeight := atomic.LoadUint32(&s.bestHeight)
 	htlcErr := link.CheckHtlcTransit(
 		htlc.PaymentHash, htlc.Amount, htlc.Expiry, currentHeight,
+		htlc.CustomRecords,
 	)
 	if htlcErr != nil {
 		log.Errorf("Link %v policy for local forward not "+
@@ -2887,10 +2888,9 @@ func (s *Switch) handlePacketAdd(packet *htlcPacket,
 			failure = link.CheckHtlcForward(
 				htlc.PaymentHash, packet.incomingAmount,
 				packet.amount, packet.incomingTimeout,
-				packet.outgoingTimeout,
-				packet.inboundFee,
-				currentHeight,
-				packet.originalOutgoingChanID,
+				packet.outgoingTimeout, packet.inboundFee,
+				currentHeight, packet.originalOutgoingChanID,
+				htlc.CustomRecords,
 			)
 		}