igb: fix TDBAL register show incorrect value

Fixed a typo which caused the registers dump function to read the
RDBAL register when printing TDBAL register values.
Signed-off-by: Gal Hammer <ghammer@redhat.com>
Tested-by: David Switzer <david.switzer@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/igb/igb_main.c

@@ -316,7 +316,7 @@ static void igb_regdump(struct e1000_hw *hw, struct igb_reg_info *reginfo)
 		break;
 	case E1000_TDBAL(0):
 		for (n = 0; n < 4; n++)
-			regs[n] = rd32(E1000_RDBAL(n));
+			regs[n] = rd32(E1000_TDBAL(n));
 		break;
 	case E1000_TDBAH(0):
 		for (n = 0; n < 4; n++)