htlcswitch/link: add ChannelPoint() to retrieve the channel outpoint.

This function will be used in the switch to retrieve the channel point for a link,
allowing the switch to retrieve individual channels from the database.

htlcswitch/link.go

@@ -9,6 +9,7 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/btcsuite/btcd/wire"
 	"github.com/davecgh/go-spew/spew"
 	"github.com/go-errors/errors"
 	"github.com/lightningnetwork/lnd/channeldb"
@@ -1743,6 +1744,12 @@ func (l *channelLink) Peer() lnpeer.Peer {
 	return l.cfg.Peer
 }
 
+// ChannelPoint returns the channel outpoint for the channel link.
+// NOTE: Part of the ChannelLink interface.
+func (l *channelLink) ChannelPoint() *wire.OutPoint {
+	return l.channel.ChannelPoint()
+}
+
 // ShortChanID returns the short channel ID for the channel link. The short
 // channel ID encodes the exact location in the main chain that the original
 // funding output can be found.