net: ethernet: lantiq_etop: remove unused variable

Remove a variable that has never been used.
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Link: https://patch.msgid.link/20240815074956.155224-1-olek2@wp.plSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/lantiq_etop.c

@@ -95,7 +95,6 @@ struct ltq_etop_priv {
 	struct mii_bus *mii_bus;
 
 	struct ltq_etop_chan ch[MAX_DMA_CHAN];
-	int tx_free[MAX_DMA_CHAN >> 1];
 
 	int tx_burst_len;
 	int rx_burst_len;