blockchain: Remove error from LatestBlockLocator.

This removes the error return from the LatestBlockLocator function since
it can never fail and ends up causing unneeded error checking.

blockchain/chain.go

@@ -1886,11 +1886,11 @@ func (b *BlockChain) BlockLocatorFromHash(hash *chainhash.Hash) BlockLocator {
 // main (best) chain.
 //
 // This function is safe for concurrent access.
-func (b *BlockChain) LatestBlockLocator() (BlockLocator, error) {
+func (b *BlockChain) LatestBlockLocator() BlockLocator {
 	b.chainLock.RLock()
 	locator := b.bestChain.BlockLocator(nil)
 	b.chainLock.RUnlock()
-	return locator, nil
+	return locator
 }
 
 // extractDeploymentIDVersions returns a map of all deployment IDs within the

internal/netsync/manager.go

@@ -362,12 +362,7 @@ func (m *SyncManager) startSync() {
 		// to send.
 		m.requestedBlocks = make(map[chainhash.Hash]struct{})
 
-		blkLocator, err := m.cfg.Chain.LatestBlockLocator()
-		if err != nil {
-			log.Errorf("Failed to get block locator for the latest block: %v",
-				err)
-			return
-		}
+		blkLocator := m.cfg.Chain.LatestBlockLocator()
 		locator := chainBlockLocatorToHashes(blkLocator)
 
 		log.Infof("Syncing to block height %d from peer %v",
@@ -1009,17 +1004,12 @@ func (m *SyncManager) handleBlockMsg(bmsg *blockMsg) {
 	onMainChain := !isOrphan && forkLen == 0
 	if isOrphan {
 		orphanRoot := m.orphanRoot(blockHash)
-		blkLocator, err := m.cfg.Chain.LatestBlockLocator()
+		blkLocator := m.cfg.Chain.LatestBlockLocator()
+		locator := chainBlockLocatorToHashes(blkLocator)
+		err := peer.PushGetBlocksMsg(locator, orphanRoot)
 		if err != nil {
-			log.Warnf("Failed to get block locator for the latest block: %v",
+			log.Warnf("Failed to push getblocksmsg for the latest block: %v",
 				err)
-		} else {
-			locator := chainBlockLocatorToHashes(blkLocator)
-			err = peer.PushGetBlocksMsg(locator, orphanRoot)
-			if err != nil {
-				log.Warnf("Failed to push getblocksmsg for the latest block: "+
-					"%v", err)
-			}
 		}
 	} else {
 		// When the block is not an orphan, log information about it and