p2p/enode: use localItemKey for local sequence number

I added localItemKey for this purpose in ethereum#18963, but then
forgot to actually use it. This changes the database layout
yet again and requires bumping the version number.

p2p/enode/nodedb.go

@@ -57,7 +57,7 @@ const (
 const (
 	dbNodeExpiration = 24 * time.Hour // Time after which an unseen node should be dropped.
 	dbCleanupCycle   = time.Hour      // Time period for running the expiration task.
-	dbVersion        = 8
+	dbVersion        = 9
 )
 
 var zeroIP = make(net.IP, 16)
@@ -380,12 +380,12 @@ func (db *DB) UpdateFindFails(id ID, ip net.IP, fails int) error {
 
 // LocalSeq retrieves the local record sequence counter.
 func (db *DB) localSeq(id ID) uint64 {
-	return db.fetchUint64(nodeItemKey(id, zeroIP, dbLocalSeq))
+	return db.fetchUint64(localItemKey(id, dbLocalSeq))
 }
 
 // storeLocalSeq stores the local record sequence counter.
 func (db *DB) storeLocalSeq(id ID, n uint64) {
-	db.storeUint64(nodeItemKey(id, zeroIP, dbLocalSeq), n)
+	db.storeUint64(localItemKey(id, dbLocalSeq), n)
 }
 
 // QuerySeeds retrieves random nodes to be used as potential seed nodes

p2p/enode/nodedb_test.go

@@ -71,7 +71,7 @@ func TestDBNodeItemKey(t *testing.T) {
 	if id != keytestID {
 		t.Errorf("splitNodeItemKey returned wrong ID: %v", id)
 	}
-	if !bytes.Equal(ip, wantIP) {
+	if !ip.Equal(wantIP) {
 		t.Errorf("splitNodeItemKey returned wrong IP: %v", ip)
 	}
 	if field != wantField {