net: stmmac: fix a possible endless loop

It forgot to reduce the value of the variable retry in a while loop
in the ethqos_configure() function. It may cause an endless loop and
without timeout.

Fixes: a7c30e62 ("net: stmmac: Add driver for Qualcomm ethqos")
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c

@@ -413,6 +413,7 @@ static int ethqos_configure(struct qcom_ethqos *ethqos)
 			dll_lock = rgmii_readl(ethqos, SDC4_STATUS);
 			if (dll_lock & SDC4_STATUS_DLL_LOCK)
 				break;
+			retry--;
 		} while (retry > 0);
 		if (!retry)
 			dev_err(&ethqos->pdev->dev,