log/sockstatlog: only start once; don't copy ticker

Signed-off-by: Will Norris <will@tailscale.com>

ipn/ipnlocal/local.go

@@ -1448,10 +1448,6 @@ func (b *LocalBackend) Start(opts ipn.Options) error {
 
 	b.e.SetNetInfoCallback(b.setNetInfo)
 
-	if b.sockstatLogger != nil {
-		b.sockstatLogger.Start()
-	}
-
 	blid := b.backendLogID
 	b.logf("Backend: logs: be:%v fe:%v", blid, opts.FrontendLogID)
 	b.send(ipn.Notify{BackendLogID: &blid})