e1000e: use hardware default values for Transmit Control register

This code snippet is simply writing default values to the register which is
unnecessary since the values are programmed into the register by default.
There is a special case for 80003es2lan needing the Retransmit on Late
Collision bit set but that is also done in e1000_init_hw_80003es2lan().
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000e/netdev.c

@@ -2770,7 +2770,7 @@ static void e1000_configure_tx(struct e1000_adapter *adapter)
 	struct e1000_hw *hw = &adapter->hw;
 	struct e1000_ring *tx_ring = adapter->tx_ring;
 	u64 tdba;
-	u32 tdlen, tctl, tarc;
+	u32 tdlen, tarc;
 
 	/* Setup the HW Tx Head and Tail descriptor pointers */
 	tdba = tx_ring->dma;
@@ -2808,12 +2808,6 @@ static void e1000_configure_tx(struct e1000_adapter *adapter)
 	/* erratum work around: set txdctl the same for both queues */
 	ew32(TXDCTL(1), er32(TXDCTL(0)));
 
-	/* Program the Transmit Control Register */
-	tctl = er32(TCTL);
-	tctl &= ~E1000_TCTL_CT;
-	tctl |= E1000_TCTL_PSP | E1000_TCTL_RTLC |
-		(E1000_COLLISION_THRESHOLD << E1000_CT_SHIFT);
-
 	if (adapter->flags & FLAG_TARC_SPEED_MODE_BIT) {
 		tarc = er32(TARC(0));
 		/*
@@ -2845,8 +2839,6 @@ static void e1000_configure_tx(struct e1000_adapter *adapter)
 	/* enable Report Status bit */
 	adapter->txd_cmd |= E1000_TXD_CMD_RS;
 
-	ew32(TCTL, tctl);
-
 	e1000e_config_collision_dist(hw);
 }