iwlagn: make iwlagn_wait_notification return error code

We're unlikely to care about the actual time spent
waiting, so make the function return an error code
which is less error prone in coding new uses.

Also, while at it, mark __must_check.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>

drivers/net/wireless/iwlwifi/iwl-agn-lib.c

@@ -2272,9 +2272,9 @@ void iwlagn_init_notification_wait(struct iwl_priv *priv,
 	spin_unlock_bh(&priv->_agn.notif_wait_lock);
 }
 
-signed long iwlagn_wait_notification(struct iwl_priv *priv,
-				     struct iwl_notification_wait *wait_entry,
-				     unsigned long timeout)
+int iwlagn_wait_notification(struct iwl_priv *priv,
+			     struct iwl_notification_wait *wait_entry,
+			     unsigned long timeout)
 {
 	int ret;
 
@@ -2286,7 +2286,10 @@ signed long iwlagn_wait_notification(struct iwl_priv *priv,
 	list_del(&wait_entry->list);
 	spin_unlock_bh(&priv->_agn.notif_wait_lock);
 
-	return ret;
+	/* return value is always >= 0 */
+	if (ret <= 0)
+		return -ETIMEDOUT;
+	return 0;
 }
 
 void iwlagn_remove_notification(struct iwl_priv *priv,

drivers/net/wireless/iwlwifi/iwl-agn-rxon.c

@@ -73,13 +73,9 @@ static int iwlagn_disable_pan(struct iwl_priv *priv,
 		IWL_ERR(priv, "Error disabling PAN (%d)\n", ret);
 		iwlagn_remove_notification(priv, &disable_wait);
 	} else {
-		signed long wait_res;
-
-		wait_res = iwlagn_wait_notification(priv, &disable_wait, HZ);
-		if (wait_res == 0) {
+		ret = iwlagn_wait_notification(priv, &disable_wait, HZ);
+		if (ret)
 			IWL_ERR(priv, "Timed out waiting for PAN disable\n");
-			ret = -EIO;
-		}
 	}
 
 	return ret;

drivers/net/wireless/iwlwifi/iwl-agn.h

@@ -343,7 +343,7 @@ iwlagn_init_notification_wait(struct iwl_priv *priv,
 					 struct iwl_rx_packet *pkt,
 					 void *data),
 			      void *fn_data);
-signed long __releases(wait_entry)
+int __must_check __releases(wait_entry)
 iwlagn_wait_notification(struct iwl_priv *priv,
 			 struct iwl_notification_wait *wait_entry,
 			 unsigned long timeout);