Fix a few vet warnings (#5674)

command/operator_migrate.go

@@ -184,6 +184,7 @@ func (c *OperatorMigrateCommand) migrate(config *migratorConfig) error {
 
 	select {
 	case err := <-doneCh:
+		cancelFunc()
 		return err
 	case <-c.ShutdownCh:
 		c.UI.Output("==> Migration shutdown triggered\n")
@@ -191,7 +192,6 @@ func (c *OperatorMigrateCommand) migrate(config *migratorConfig) error {
 		<-doneCh
 		return errAbort
 	}
-	return nil
 }
 
 // migrateAll copies all keys in lexicographic order.

command/server.go

@@ -1842,7 +1842,6 @@ func (c *ServerCommand) storageMigrationActive(backend physical.Backend) bool {
 			return true
 		}
 	}
-	return false
 }
 
 type StorageMigrationStatus struct {

vault/token_store.go

@@ -905,8 +905,6 @@ func (ts *TokenStore) create(ctx context.Context, entry *logical.TokenEntry) err
 	default:
 		return fmt.Errorf("cannot create a token of type %d", entry.Type)
 	}
-
-	return errors.New("unreachable code")
 }
 
 // Store is used to store an updated token entry without writing the