fix: fix some code as comment

cmd/geth/snapshot.go

@@ -43,6 +43,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
 	"github.com/ethereum/go-ethereum/triedb"
@@ -225,8 +226,6 @@ the expected order for the overlay tree migration.
 	}
 )
 
-const minBlockAmountReserved uint64 = 90000
-
 func accessDb(ctx *cli.Context, stack *node.Node) (ethdb.Database, error) {
 	//The layer of tries trees that keep in memory.
 	TriesInMemory := int(ctx.Uint64(utils.TriesInMemoryFlag.Name))
@@ -253,7 +252,6 @@ func accessDb(ctx *cli.Context, stack *node.Node) (ethdb.Database, error) {
 	if dbScheme == rawdb.PathScheme {
 		config = &triedb.Config{
 			PathDB: utils.PathDBConfigAddJournalFilePath(stack, pathdb.ReadOnly),
-			Cache:  0,
 		}
 	} else if dbScheme == rawdb.HashScheme {
 		config = triedb.HashDefaults
@@ -346,10 +344,9 @@ func pruneBlock(ctx *cli.Context) error {
 	stack, config = makeConfigNode(ctx)
 	defer stack.Close()
 	blockAmountReserved = ctx.Uint64(utils.BlockAmountReserved.Name)
-	if blockAmountReserved < minBlockAmountReserved {
-		return fmt.Errorf("block-amount-reserved must be greater than or equal to %d", minBlockAmountReserved)
+	if blockAmountReserved < params.FullImmutabilityThreshold {
+		return fmt.Errorf("block-amount-reserved must be greater than or equal to %d", params.FullImmutabilityThreshold)
 	}
-	log.Info("blockAmountReserved xxx", "blockAmountReserved", blockAmountReserved)
 	chaindb, err = accessDb(ctx, stack)
 	if err != nil {
 		return err