all: fix spelling errors

trie/hasher.go

@@ -52,7 +52,7 @@ func returnHasherToPool(h *hasher) {
 // hash collapses a node down into a hash node, also returning a copy of the
 // original node initialzied with the computed hash to replace the original one.
 func (h *hasher) hash(n node, db DatabaseWriter, force bool) (node, node, error) {
-	// If we're not storing the node, just hashing, use avaialble cached data
+	// If we're not storing the node, just hashing, use available cached data
 	if hash, dirty := n.cache(); hash != nil {
 		if db == nil {
 			return hash, n, nil