cli/command/registry: loginClientSide: use locally defined message

The "Service.Auth" pretended to return a message from the registry,
but the message returned is hard-coded in the registry package.

Remove its use to make this more transparent, and not to pretend
this is anything returned by the registry.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/registry/login.go

@@ -263,13 +263,13 @@ func loginClientSide(ctx context.Context, auth registrytypes.AuthConfig) (*regis
 		return nil, err
 	}
 
-	status, token, err := svc.Auth(ctx, &auth, command.UserAgent())
+	_, token, err := svc.Auth(ctx, &auth, command.UserAgent())
 	if err != nil {
 		return nil, err
 	}
 
 	return &registrytypes.AuthenticateOKBody{
-		Status:        status,
+		Status:        "Login Succeeded",
 		IdentityToken: token,
 	}, nil
 }