htlcswitch+lnwallet: remove PaymentDescriptor from ReceiveRevocation returns

This is part of a systematic removal of PaymentDescriptor from the public
API of the lnwallet package. This marks the last change needed before we
make the PaymentDescriptor structure private.

htlcswitch/link.go

@@ -2321,8 +2321,7 @@ func (l *channelLink) handleUpstreamMsg(msg lnwire.Message) {
 
 		// We now process the message and advance our remote commit
 		// chain.
-		fwdPkg, _, _, remoteHTLCs, err := l.channel.
-			ReceiveRevocation(msg)
+		fwdPkg, remoteHTLCs, err := l.channel.ReceiveRevocation(msg)
 		if err != nil {
 			// TODO(halseth): force close?
 			l.failf(

htlcswitch/link_isolated_test.go

@@ -129,7 +129,7 @@ func (l *linkTestContext) receiveRevAndAckAliceToBob() {
 		l.t.Fatalf("expected RevokeAndAck, got %T", msg)
 	}
 
-	_, _, _, _, err := l.bobChannel.ReceiveRevocation(rev)
+	_, _, err := l.bobChannel.ReceiveRevocation(rev)
 	if err != nil {
 		l.t.Fatalf("bob failed receiving revocation: %v", err)
 	}

htlcswitch/link_test.go

@@ -2335,7 +2335,7 @@ func handleStateUpdate(link *channelLink,
 	if !ok {
 		return fmt.Errorf("expected RevokeAndAck got %T", msg)
 	}
-	_, _, _, _, err = remoteChannel.ReceiveRevocation(revoke)
+	_, _, err = remoteChannel.ReceiveRevocation(revoke)
 	if err != nil {
 		return fmt.Errorf("unable to receive "+
 			"revocation: %v", err)
@@ -2389,7 +2389,7 @@ func updateState(batchTick chan time.Time, link *channelLink,
 		return fmt.Errorf("expected RevokeAndAck got %T",
 			msg)
 	}
-	_, _, _, _, err = remoteChannel.ReceiveRevocation(revoke)
+	_, _, err = remoteChannel.ReceiveRevocation(revoke)
 	if err != nil {
 		return fmt.Errorf("unable to receive "+
 			"revocation: %v", err)
@@ -3643,7 +3643,7 @@ func TestChannelLinkTrimCircuitsRemoteCommit(t *testing.T) {
 	rev, _, _, err := harness.bobChannel.RevokeCurrentCommitment()
 	require.NoError(t, err, "unable to revoke current commitment")
 
-	_, _, _, _, err = alice.channel.ReceiveRevocation(rev)
+	_, _, err = alice.channel.ReceiveRevocation(rev)
 	require.NoError(t, err, "unable to receive revocation")
 
 	// Restart Alice's link, which simulates a disconnection with the remote