mac80211: fix dot11MulticastTransmittedFrameCount tested address

dot11MulticastTransmittedFrameCount should be updated according
to the DA, which might be different from A1. Checking A1 results
in the counter being 0 in case of station, as to-DS data frames
use A1 for the BSSID.

This behaviour is defined in state machines, specifically in the
sta_tx_dcf_3.1d(10) description of 802.11-2012.
Signed-off-by: NEliad Peller <eliad@wizery.com>
[rewrite commit message]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

net/mac80211/status.c

@@ -862,7 +862,7 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
 	    (info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED)) {
 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
 			local->dot11TransmittedFrameCount++;
-			if (is_multicast_ether_addr(hdr->addr1))
+			if (is_multicast_ether_addr(ieee80211_get_DA(hdr)))
 				local->dot11MulticastTransmittedFrameCount++;
 			if (retry_count > 0)
 				local->dot11RetryCount++;