ipw2x00: make ipw_qos_association_resp() void

Fix the following coccicheck warning:

drivers/net/wireless/intel/ipw2x00/ipw2200.c:7048:5-8: Unneeded
variable: "ret". Return "0" on line 7055
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200410090850.27025-1-yanaijie@huawei.com

drivers/net/wireless/intel/ipw2x00/ipw2200.c

@@ -7042,23 +7042,22 @@ static int ipw_qos_association(struct ipw_priv *priv,
 * off the network from the associated setting, adjust the QoS
 * setting
 */
-static int ipw_qos_association_resp(struct ipw_priv *priv,
+static void ipw_qos_association_resp(struct ipw_priv *priv,
 				    struct libipw_network *network)
 {
-	int ret = 0;
 	unsigned long flags;
 	u32 size = sizeof(struct libipw_qos_parameters);
 	int set_qos_param = 0;
 
 	if ((priv == NULL) || (network == NULL) ||
 	    (priv->assoc_network == NULL))
-		return ret;
+		return;
 
 	if (!(priv->status & STATUS_ASSOCIATED))
-		return ret;
+		return;
 
 	if ((priv->ieee->iw_mode != IW_MODE_INFRA))
-		return ret;
+		return;
 
 	spin_lock_irqsave(&priv->ieee->lock, flags);
 	if (network->flags & NETWORK_HAS_QOS_PARAMETERS) {
@@ -7088,8 +7087,6 @@ static int ipw_qos_association_resp(struct ipw_priv *priv,
 
 	if (set_qos_param == 1)
 		schedule_work(&priv->qos_activate);
-
-	return ret;
 }
 
 static u32 ipw_qos_get_burst_duration(struct ipw_priv *priv)