Description of problem:
The per-vm specific uefi vars nvram should be deleted when the vm is.
This should normally not cause any harm, but if a vm is created with the same name as a previously deleted vm, but with a incompatible uefi (e.g. different architecture), this could cause problems.

Version-Release number of selected component (if applicable):
libvirt 1.2.21
virt-manager 1.2.1

How reproducible:
Always

Steps to Reproduce:
1. Create a VM named generic
2. Delete the VM
3. ls /var/lib/libvirt/qemu/nvram

Actual results:
generic_VARS.fd still remains there

Expected results:
generic_VARS.fd is deleted

Additional info:
Arch Linux