e1000e: consistent use of Rx/Tx vs. RX/TX/rx/tx in comments/logs

Some minor comment errors and whitespace issues discovered while looking
into this are also addressed.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/e1000e/phy.c b/drivers/net/e1000e/phy.c
index eb6cbad..326788e 100644
--- a/drivers/net/e1000e/phy.c
+++ b/drivers/net/e1000e/phy.c
@@ -640,7 +640,7 @@
 	s32 ret_val;
 	u16 phy_data;
 
-	/* Enable CRS on TX. This must be set for half-duplex operation. */
+	/* Enable CRS on Tx. This must be set for half-duplex operation. */
 	ret_val = e1e_rphy(hw, I82577_CFG_REG, &phy_data);
 	if (ret_val)
 		goto out;