mac80211: fix offchannel TX cookie matching

commit 28a1bcdb57d50f3038a255741ecc83e391e5282e upstream.

When I introduced in-kernel off-channel TX I
introduced a bug -- the work can't be canceled
again because the code clear the skb pointer.
Fix this by keeping track separately of whether
TX status has already been reported.

Reported-by: Jouni Malinen <j@w1.fi>
Tested-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/mac80211/work.c b/net/mac80211/work.c
index d2e7f0e..dc8ec05 100644
--- a/net/mac80211/work.c
+++ b/net/mac80211/work.c
@@ -553,7 +553,7 @@
 		/*
 		 * After this, offchan_tx.frame remains but now is no
 		 * longer a valid pointer -- we still need it as the
-		 * cookie for canceling this work.
+		 * cookie for canceling this work/status matching.
 		 */
 		ieee80211_tx_skb(wk->sdata, wk->offchan_tx.frame);