remove unused function (#3657)

vault/mount.go

@@ -1,8 +1,6 @@
 package vault
 
 import (
-	"crypto/sha1"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"sort"
@@ -125,16 +123,6 @@ func (t *MountTable) shallowClone() *MountTable {
 	return mt
 }
 
-// Hash is used to generate a hash value for the mount table
-func (t *MountTable) Hash() ([]byte, error) {
-	buf, err := json.Marshal(t)
-	if err != nil {
-		return nil, err
-	}
-	hash := sha1.Sum(buf)
-	return hash[:], nil
-}
-
 // setTaint is used to set the taint on given entry
 func (t *MountTable) setTaint(path string, value bool) *MountEntry {
 	n := len(t.Entries)