contractcourt: remove TODO for checking double spends from PublishTx

contractcourt/channel_arbitrator.go

@@ -449,7 +449,6 @@ func (c *ChannelArbitrator) stateStep(bestHeight uint32, bestHash *chainhash.Has
 		// At this point, we'll now broadcast the commitment
 		// transaction itself.
 		if err := c.cfg.PublishTx(closeTx); err != nil {
-			// TODO(roasbeef): need to check for errors (duplicate)
 			log.Errorf("ChannelArbitrator(%v): unable to broadcast "+
 				"close tx: %v", c.cfg.ChanPoint, err)
 			return StateError, closeTx, err

contractcourt/contract_resolvers.go

@@ -582,7 +582,6 @@ func (h *htlcSuccessResolver) Resolve() (ContractResolver, error) {
 	//
 	// TODO(roasbeef): after changing sighashes send to tx bundler
 	if err := h.PublishTx(h.htlcResolution.SignedSuccessTx); err != nil {
-		// TODO(roasbeef): detect double spends
 		return nil, err
 	}