mac80211: ignore CSA to same channel

If the AP is confused and starts doing a CSA to the same channel,
just ignore that request instead of trying to act it out since it
was likely sent in error anyway.

In the case of the bug I was investigating the GO was misbehaving
and sending out a beacon with CSA IEs still included after having
actually done the channel switch.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index c0e089c..8d53d65 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -464,6 +464,7 @@
 	unsigned int flags;
 
 	bool csa_waiting_bcn;
+	bool csa_ignored_same_chan;
 
 	bool beacon_crc_valid;
 	u32 beacon_crc;