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.h b/net/mac80211/wpa.h
index baba060..07e33f8 100644
--- a/net/mac80211/wpa.h
+++ b/net/mac80211/wpa.h
@@ -32,5 +32,7 @@
 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx);
 ieee80211_rx_result
 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx);
+ieee80211_tx_result
+ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx);
 
 #endif /* WPA_H */