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>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.h b/drivers/net/wireless/iwlwifi/iwl-agn.h
index b9871c4..ba90aa4 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.h
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.h
@@ -343,7 +343,7 @@
 					 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);