Merge pull request #3313 from wpaulino/neutrino-cleanup-panic

lnd: prevent panic on nil neutrino cleanup

chainregistry.go

@@ -713,6 +713,7 @@ func initNeutrinoBackend(chainDir string) (*neutrino.ChainService, func(), error
 		cfg.NeutrinoMode.AssertFilterHeader,
 	)
 	if err != nil {
+		db.Close()
 		return nil, nil, err
 	}
 
@@ -754,6 +755,7 @@ func initNeutrinoBackend(chainDir string) (*neutrino.ChainService, func(), error
 
 	neutrinoCS, err := neutrino.NewChainService(config)
 	if err != nil {
+		db.Close()
 		return nil, nil, fmt.Errorf("unable to create neutrino light "+
 			"client: %v", err)
 	}

lnd.go

@@ -203,10 +203,10 @@ func Main() error {
 		neutrinoBackend, neutrinoCleanUp, err := initNeutrinoBackend(
 			mainChain.ChainDir,
 		)
-		defer neutrinoCleanUp()
 		if err != nil {
 			return err
 		}
+		defer neutrinoCleanUp()
 		neutrinoCS = neutrinoBackend
 	}