Missed some code that was left floating around in the DCB configuration
for the TXDCTL register.  As a result the register was being messed with in
two different spots when we only needed to do the change once.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NRoss Brattain <ross.b.brattain@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>