Fix vlan ID detection in udev interface driver
Fix vlan ID detection in udev interface driver

Instead of guessing it from the interface name, look into
/proc/net/vlan/<interface>.

This works for devices not named <real_device>.<vlan ID>,
avoiding an error flood when virt-manager keeps asking about
them every second:

https://bugzilla.redhat.com/show_bug.cgi?id=966329

shugaoye/libvirt,fabianfreyer/libvirt,shugaoye/libvirt,crobinso/libvirt,jardasgit/libvirt,libvirt/libvirt,elmarco/libvirt,eskultety/libvirt,taget/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,eskultety/libvirt,jfehlig/libvirt,datto/libvirt,crobinso/libvirt,rlaager/libvirt,zippy2/libvirt,andreabolognani/libvirt,taget/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,olafhering/libvirt,nertpinx/libvirt,zippy2/libvirt,andreabolognani/libvirt,taget/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,shugaoye/libvirt,taget/libvirt,nertpinx/libvirt,jardasgit/libvirt,elmarco/libvirt,agx/libvirt,datto/libvirt,shugaoye/libvirt,crobinso/libvirt,libvirt/libvirt,olafhering/libvirt,crobinso/libvirt,elmarco/libvirt,olafhering/libvirt,agx/libvirt,jardasgit/libvirt,jardasgit/libvirt,libvirt/libvirt,VenkatDatta/libvirt,eskultety/libvirt,jfehlig/libvirt,zippy2/libvirt,rlaager/libvirt,olafhering/libvirt,fabianfreyer/libvirt,agx/libvirt,andreabolognani/libvirt,rlaager/libvirt,zippy2/libvirt,datto/libvirt,andreabolognani/libvirt,elmarco/libvirt,jfehlig/libvirt,elmarco/libvirt,andreabolognani/libvirt,datto/libvirt,shugaoye/libvirt,jfehlig/libvirt,agx/libvirt,taget/libvirt,eskultety/libvirt,nertpinx/libvirt,datto/libvirt,rlaager/libvirt,rlaager/libvirt,libvirt/libvirt,eskultety/libvirt,agx/libvirt