ath9k: Fix RX filters in channel contexts

Maintain the RX filter on a per-channel-context
basis and not globally. Not doing so was resulting
in incorrect filter calculation.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 18e5e91..a202859 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1427,7 +1427,10 @@
 	changed_flags &= SUPPORTED_FILTERS;
 	*total_flags &= SUPPORTED_FILTERS;
 
-	sc->rx.rxfilter = *total_flags;
+	spin_lock_bh(&sc->chan_lock);
+	sc->cur_chan->rxfilter = *total_flags;
+	spin_unlock_bh(&sc->chan_lock);
+
 	ath9k_ps_wakeup(sc);
 	rfilt = ath_calcrxfilter(sc);
 	ath9k_hw_setrxfilter(sc->sc_ah, rfilt);