refactor: deal with err from ShowSubcommandHelp

cli/server/init.go

@@ -26,8 +26,7 @@ later for more advanced use cases.
 	Action: func(c *cli.Context) error {
 		host := c.Args().First()
 		if host == "" {
-			cli.ShowSubcommandHelp(c)
-			return nil
+			return cli.ShowSubcommandHelp(c)
 		}
 
 		cl, err := client.NewClientWithContext(host)

cli/server/new.go

@@ -66,8 +66,7 @@ environment variable or otherwise passing the "--env/-e" flag.
 	Action: func(c *cli.Context) error {
 		name := c.Args().First()
 		if name == "" {
-			cli.ShowSubcommandHelp(c)
-			return nil
+			return cli.ShowSubcommandHelp(c)
 		}
 
 		ctx := context.Background()

cli/server/remove.go

@@ -14,8 +14,7 @@ var serverRemoveCommand = &cli.Command{
 	Action: func(c *cli.Context) error {
 		server := c.Args().First()
 		if server == "" {
-			cli.ShowSubcommandHelp(c)
-			return nil
+			return cli.ShowSubcommandHelp(c)
 		}
 		if err := client.DeleteContext(server); err != nil {
 			logrus.Fatal(err)