net/atlantic: fix build with clang 15

[ upstream commit f25fa03ad1a9df09870b55efa8b543ca60ab1b88 ]

This variable is not used.

Fixes: 2b1472d ("net/atlantic: implement Tx path")

Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Tyler Retzlaff <roretzla@linux.microsoft.com>

drivers/net/atlantic/atl_rxtx.c

@@ -1132,10 +1132,9 @@ atl_xmit_cleanup(struct atl_tx_queue *txq)
 	if (txq != NULL) {
 		sw_ring = txq->sw_ring;
 		int head = txq->tx_head;
-		int cnt;
-		int i;
+		int cnt = head;
 
-		for (i = 0, cnt = head; ; i++) {
+		while (true) {
 			txd = &txq->hw_ring[cnt];
 
 			if (txd->dd)