mac80211: rx.c/tx.c remove more users of tx/rx_data->fc

Those functions that still use ieee80211_get_hdrlen are moved over
to use the little endian frame control.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 4788f7b..24146f3 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1025,7 +1025,7 @@
 	else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
 
-	hdrlen = ieee80211_get_hdrlen(tx->fc);
+	hdrlen = ieee80211_hdrlen(hdr->frame_control);
 	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
 		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
 		tx->ethertype = (pos[0] << 8) | pos[1];