Redirect from default WP to custom login page not working, here's the script

I added this to the theme’s function.php. I log onto the website and click on login, it still takes me to the default WP login screen.

/*
 * Newly added custom code (for reference only)
 * --------------------------------------------
 * RedirectWPLogin()
 * Redirect from default WordPress login to custom login page
 */

 add_filter('init', 'RedirectWPLogin()');
 function RedirectWPLogin()
 {
 	$request = basename($_SERVER['REQUEST_URI']);
	if ($request == 'wp-login.php'):
		wp_redirect(site_url('/login'));
		exit();
	endif;
 }

Can anyone please help me in debugging this problem?

Thanks,
Hal