uefi: Use _cleanup_free in one more place
uefi: Use _cleanup_free in one more place

fwupd/fwupd,hughsie/fwupd,fwupd/fwupd,vathpela/fwupd,hughsie/fwupd,vathpela/fwupd,vathpela/fwupd,fwupd/fwupd,fwupd/fwupd,hughsie/fwupd,vathpela/fwupd,hughsie/fwupd