x11-randr: fix leak on vdagent_x11 destroy

In vdagent_x11_destroy(), only x11->randr.failed_conf is freed and x11->randr.{res, outputs, crtcs} are left allocated.

To fix it, create a new function vdagent_x11_randr_destroy() that frees all randr resources, and call it from vdagent_x11_destroy().

Signed-off-by: Jakub Janků jjanku@redhat.com