Try the below code,
function remove_menuitems_from_admin_bar() {
global $wp_admin_bar;
$wp_admin_bar->remove_menu('wp-logo');
$wp_admin_bar->remove_menu('user-info');
$wp_admin_bar->remove_menu('site-name');
$wp_admin_bar->remove_menu('dashboard');
$wp_admin_bar->remove_menu('edit-profile', 'user-actions');
$wp_admin_bar->remove_menu('my-account');
$user_id = get_current_user_id();
$current_user = wp_get_current_user();
if (!$user_id)
return;
$avatar = get_avatar($user_id, 26);
$howdy = sprintf(__('Howdy, %s'), '<span class="display-name">' . $current_user->display_name . '</span>');
$class = empty($avatar) ? '' : 'with-avatar';
$wp_admin_bar->add_menu(array(
'id' => 'my-account',
'parent' => 'top-secondary',
'title' => $howdy . $avatar,
'meta' => array(
'class' => $class,
),
));
}
add_action('wp_before_admin_bar_render', 'remove_menuitems_from_admin_bar');
Hope this helps.