[shell] use constant for hdd of type (#6337)

use constant for hdd of type

weed/shell/command_cluster_check.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"github.com/seaweedfs/seaweedfs/weed/storage/types"
 	"io"
 
 	"github.com/seaweedfs/seaweedfs/weed/cluster"
@@ -79,7 +80,7 @@ func (c *commandClusterCheck) Do(args []string, commandEnv *CommandEnv, writer i
 
 	if len(filers) > 0 {
 		genericDiskInfo, genericDiskInfoOk := topologyInfo.DiskInfos[""]
-		hddDiskInfo, hddDiskInfoOk := topologyInfo.DiskInfos["hdd"]
+		hddDiskInfo, hddDiskInfoOk := topologyInfo.DiskInfos[types.HddType]
 
 		if !genericDiskInfoOk && !hddDiskInfoOk {
 			return fmt.Errorf("filer metadata logs need generic or hdd disk type to be defined")