various: use NodePublic.AsNodeKey() instead of tailcfg.NodeKeyFromNodePublic()

Updates #3206

Signed-off-by: David Anderson <danderson@tailscale.com>

control/controlclient/direct.go

@@ -357,8 +357,8 @@ func (c *Direct) doLogin(ctx context.Context, opt loginOpt) (mustRegen bool, new
 	now := time.Now().Round(time.Second)
 	request := tailcfg.RegisterRequest{
 		Version:    1,
-		OldNodeKey: tailcfg.NodeKeyFromNodePublic(oldNodeKey),
-		NodeKey:    tailcfg.NodeKeyFromNodePublic(tryingNewKey.Public()),
+		OldNodeKey: oldNodeKey.AsNodeKey(),
+		NodeKey:    tryingNewKey.Public().AsNodeKey(),
 		Hostinfo:   hostinfo,
 		Followup:   opt.URL,
 		Timestamp:  &now,
@@ -595,7 +595,7 @@ func (c *Direct) sendMapRequest(ctx context.Context, maxPolls int, cb func(*netm
 	request := &tailcfg.MapRequest{
 		Version:       tailcfg.CurrentMapRequestVersion,
 		KeepAlive:     c.keepAlive,
-		NodeKey:       tailcfg.NodeKeyFromNodePublic(persist.PrivateNodeKey.Public()),
+		NodeKey:       persist.PrivateNodeKey.Public().AsNodeKey(),
 		DiscoKey:      c.discoPubKey,
 		Endpoints:     epStrs,
 		EndpointTypes: epTypes,

control/controlclient/map.go

@@ -110,7 +110,7 @@ func (ms *mapSession) netmapForResponse(resp *tailcfg.MapResponse) *netmap.Netwo
 	}
 
 	nm := &netmap.NetworkMap{
-		NodeKey:         tailcfg.NodeKeyFromNodePublic(ms.privateNodeKey.Public()),
+		NodeKey:         ms.privateNodeKey.Public().AsNodeKey(),
 		PrivateKey:      ms.privateNodeKey,
 		MachineKey:      ms.machinePubKey,
 		Peers:           resp.Peers,