Updated the update method on the treiHasher object.

restricted/types/hashing.go

@@ -62,7 +62,7 @@ func prefixedRlpHash(prefix byte, x interface{}) (h core.Hash) {
 // This is internal, do not use.
 type TrieHasher interface {
 	Reset()
-	Update([]byte, []byte) error
+	Update([]byte, []byte)
 	Hash() core.Hash
 }