[PATCH] e1000: Fix bit 22 (TXDCTL) for 82571 & 82572 controllers

Removed duplicate code, TXDCTL and TXDCTL_COUNT_DESC are the same bit and there is no need to set it twice.

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>