fatal error in trying to update function.php with social icon

Hi,

I tried using this code to use a custom image for a social icon (below) and got the following:

Fatal error: Cannot redeclare avia_add_custom_social_icon() (previously declared in /home/marshallcrossman/public_html/wp-content/themes/enfold/functions.php:524) in /home/marshallcrossman/public_html/wp-content/themes/enfold/functions.php on line 533

Can you assist?

Thanks

function avia_add_custom_social_icon($icons) {
$icons[‘Kriesi’] = ‘kriesi’;
return $icons;
}
add_filter(‘avf_social_icons_options’,’avia_add_custom_social_icon’, 10, 1);