net: ethernet: 8390: axnet_cs: remove unused xfer_count variable

clang with W=1 reports
drivers/net/ethernet/8390/axnet_cs.c:653:9: error: variable
  'xfer_count' set but not used [-Werror,-Wunused-but-set-variable]
    int xfer_count = count;
        ^
This variable is not used so remove it.
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230327235423.1777590-1-trix@redhat.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/8390/axnet_cs.c

@@ -650,7 +650,6 @@ static void block_input(struct net_device *dev, int count,
 {
     unsigned int nic_base = dev->base_addr;
     struct ei_device *ei_local = netdev_priv(dev);
-    int xfer_count = count;
     char *buf = skb->data;
 
     if ((netif_msg_rx_status(ei_local)) && (count != 4))
@@ -662,9 +661,7 @@ static void block_input(struct net_device *dev, int count,
     insw(nic_base + AXNET_DATAPORT,buf,count>>1);
     if (count & 0x01) {
 	buf[count-1] = inb(nic_base + AXNET_DATAPORT);
-	xfer_count++;
     }
-
 }
 
 /*====================================================================*/