3_aa_deny_write_to_readonly.patch:
Suppress confusing and misleading apparmor denied message when kvm/qemu
tries to open a libvirt specified readonly file (such as a cdrom) with
write permissions. libvirt uses the readonly attribute for the security
driver only, and has no way of telling kvm/qemu that the device should
be opened readonly. This fixes
https://launchpad.net/bugs/453335.