eth, node, trie: fix minor typos (ethereum#16802)

eth/backend.go

@@ -215,14 +215,14 @@ func CreateConsensusEngine(ctx *node.ServiceContext, config *ethash.Config, chai
 		return clique.New(chainConfig.Clique, db)
 	}
 	// Otherwise assume proof-of-work
-	switch {
-	case config.PowMode == ethash.ModeFake:
+	switch config.PowMode {
+	case ethash.ModeFake:
 		log.Warn("Ethash used in fake mode")
 		return ethash.NewFaker()
-	case config.PowMode == ethash.ModeTest:
+	case ethash.ModeTest:
 		log.Warn("Ethash used in test mode")
 		return ethash.NewTester()
-	case config.PowMode == ethash.ModeShared:
+	case ethash.ModeShared:
 		log.Warn("Ethash used in shared mode")
 		return ethash.NewShared()
 	default:
@@ -239,7 +239,7 @@ func CreateConsensusEngine(ctx *node.ServiceContext, config *ethash.Config, chai
 	}
 }
 
-// APIs returns the collection of RPC services the ethereum package offers.
+// APIs return the collection of RPC services the ethereum package offers.
 // NOTE, some of these services probably need to be moved to somewhere else.
 func (s *Ethereum) APIs() []rpc.API {
 	apis := ethapi.GetAPIs(s.APIBackend)

node/doc.go

@@ -59,7 +59,7 @@ using the same data directory will store this information in different subdirect
 the data directory.
 
 LevelDB databases are also stored within the instance subdirectory. If multiple node
-instances use the same data directory, openening the databases with identical names will
+instances use the same data directory, opening the databases with identical names will
 create one database for each instance.
 
 The account key store is shared among all node instances using the same data directory
@@ -84,7 +84,7 @@ directory. Mode instance A opens the database "db", node instance B opens the da
             static-nodes.json  -- devp2p static node list of instance B
             db/                -- LevelDB content for "db"
             db-2/              -- LevelDB content for "db-2"
-        B.ipc                  -- JSON-RPC UNIX domain socket endpoint of instance A
+        B.ipc                  -- JSON-RPC UNIX domain socket endpoint of instance B
         keystore/              -- account key store, used by both instances
 */
 package node

trie/trie.go

@@ -101,7 +101,7 @@ func New(root common.Hash, db *Database) (*Trie, error) {
 		db:           db,
 		originalRoot: root,
 	}
-	if (root != common.Hash{}) && root != emptyRoot {
+	if root != (common.Hash{}) && root != emptyRoot {
 		rootnode, err := trie.resolveHash(root[:], nil)
 		if err != nil {
 			return nil, err