ixgbe: Reduce VT code indent in set_vfta by introducing jump label

In order to clear the way for upcoming work I thought it best to drop the
level of indent in the ixgbe_set_vfta_generic function.  Most of the code
is held in the virtualization specific section.  So the easiest approach is
to just add a jump label and jump past the bulk of the code if it is not
enabled.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>