eth: Fix incorrect TX exit condition

trashernet/trashernet_eth.vhd

@@ -141,7 +141,7 @@ begin
 						end if;
 
 					when TXD =>
-						state <= IDLE when (mac_in.tx_mac_data_en or not mac_out.tx_active);
+						state <= IDLE when (not mac_in.tx_mac_data_en or not mac_out.tx_active);
 				end case;
 			end if;
 		end process arb;