I have been spending few hours on that issue and despite the high number of posts related to it, I cannot solve it. I have a Fedora 20 box with Nginx + PHP-FPM that worked q
Do not forget to restart php5-fpm service after changing php.ini!!
service php5-fpm restart or service php5-fpm reload
fpm prestarts php5 so it is not enough to restart nginx to have the changes applied.