mac80211: fix tx->skb NULL pointer dereference

In function ieee80211_tx_h_encrypt the var info was
initialized from tx->skb, since the fucntion
is called after the function ieee80211_tx_h_fragment
tx->skb is not valid anymore.

Signed-off-by: Yoni Divinsky <yoni.divinsky@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 422b798..b758350 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -643,3 +643,22 @@
 
 	return RX_CONTINUE;
 }
+
+ieee80211_tx_result
+ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
+{
+	struct sk_buff *skb;
+	struct ieee80211_tx_info *info = NULL;
+
+	skb_queue_walk(&tx->skbs, skb) {
+		info  = IEEE80211_SKB_CB(skb);
+
+		/* handle hw-only algorithm */
+		if (!info->control.hw_key)
+			return TX_DROP;
+	}
+
+	ieee80211_tx_set_protected(tx);
+
+	return TX_CONTINUE;
+}