Ensure GET_VLAN_VID_CMD is always defined
Ensure GET_VLAN_VID_CMD is always defined

The RHEL4 vintage header files do not define GET_VLAN_VID_CMD.
Conditionally define it in our source, since the kernel can
raise a runtime error if it isn't supported

Signed-off-by: Daniel P. Berrange <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

cbosdo/libvirt,eskultety/libvirt,elmarco/libvirt,crobinso/libvirt,libvirt/libvirt,cbosdo/libvirt,nertpinx/libvirt,taget/libvirt,zippy2/libvirt,crobinso/libvirt,olafhering/libvirt,zippy2/libvirt,libvirt/libvirt,agx/libvirt,olafhering/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,zhlcindy/libvirt-1.1.4-maintain,shugaoye/libvirt,agx/libvirt,nertpinx/libvirt,jardasgit/libvirt,nertpinx/libvirt,taget/libvirt,andreabolognani/libvirt,zhlcindy/libvirt-1.1.4-maintain,agx/libvirt,rlaager/libvirt,crobinso/libvirt,libvirt/libvirt,VenkatDatta/libvirt,datto/libvirt,eskultety/libvirt,jardasgit/libvirt,rlaager/libvirt,andreabolognani/libvirt,shugaoye/libvirt,eskultety/libvirt,crobinso/libvirt,jfehlig/libvirt,zippy2/libvirt,taget/libvirt,datto/libvirt,rlaager/libvirt,jfehlig/libvirt,jardasgit/libvirt,elmarco/libvirt,zhlcindy/libvirt-1.1.4-maintain,agx/libvirt,libvirt/libvirt,shugaoye/libvirt,nertpinx/libvirt,agx/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,zhlcindy/libvirt-1.1.4-maintain,olafhering/libvirt,VenkatDatta/libvirt,elmarco/libvirt,VenkatDatta/libvirt,zippy2/libvirt,fabianfreyer/libvirt,datto/libvirt,nertpinx/libvirt,eskultety/libvirt,zhlcindy/libvirt-1.1.4-maintain,taget/libvirt,eskultety/libvirt,shugaoye/libvirt,andreabolognani/libvirt,cbosdo/libvirt,datto/libvirt,shugaoye/libvirt,jfehlig/libvirt,cbosdo/libvirt,rlaager/libvirt,datto/libvirt,olafhering/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,rlaager/libvirt,elmarco/libvirt,taget/libvirt,jardasgit/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,elmarco/libvirt,cbosdo/libvirt