The kernel interface changed just before 2.6.34 was released.  This brings
iproute2 in line with the current changes.  The VF portion of setlink is
comprised of a set of nested attributes.

  IFLA_VFINFO_LIST (NESTED)
    IFLA_VF_INFO (NESTED)
      IFLA_VF_MAC
      IFLA_VF_VLAN
      IFLA_VF_TX_RATE
Signed-off-by: Chris Wright <chrisw@sous-sol.org>