mac80211: fix TX status cookie in HW offload case

When the off-channel TX is done with remain-on-channel
offloaded to hardware, the reported cookie is wrong as
in that case we shouldn't use the SKB as the cookie but
need to instead use the corresponding r-o-c cookie
(XOR'ed with 2 to prevent API mismatches).

Fix this by keeping track of the hw_roc_skb pointer
just for the status processing and use the correct
cookie to report in this case. We can't use the
hw_roc_skb pointer itself because it is NULL'ed when
the frame is transmitted to prevent it being used
twice.

This fixes a bug where the P2P state machine in the
supplicant gets stuck because it never gets a correct
result for its transmitted frame.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index c47d7c0..533fd32 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -953,7 +953,7 @@
 
 	struct ieee80211_channel *hw_roc_channel;
 	struct net_device *hw_roc_dev;
-	struct sk_buff *hw_roc_skb;
+	struct sk_buff *hw_roc_skb, *hw_roc_skb_for_status;
 	struct work_struct hw_roc_start, hw_roc_done;
 	enum nl80211_channel_type hw_roc_channel_type;
 	unsigned int hw_roc_duration;