[libvirt] [PATCH] fix AppArmor driver for pipe character devices

The AppArmor security driver adds only the path specified in the domain XML for character devices of type 'pipe'. It should be using <path>.in and <path>.out. We do this by creating a new vah_add_file_chardev() and use it for char devices instead of vah_add_file(). Also adjust valid_path() to accept S_FIFO (since qemu chardevs of type 'pipe' use fifos). This is https://launchpad.net/bugs/832507 -- Jamie Strandboge | http://www.canonical.com