[MAC80211]: get STA after tx radiotap snipped

Johannes Berg noticed that in __ieee80211_tx_prepare() we try to get the
STA from addr1 of the ieee80211 header when the radiotap header is actually
still at the front of the packet.  This patch defers doing that until the
radiotap header is gone.

Signed-off-by: Andy Green <andy@warmcat.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 3d57e6d..1780c24 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -959,8 +959,6 @@
 	tx->dev = dev; /* use original interface */
 	tx->local = local;
 	tx->sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-	tx->sta = sta_info_get(local, hdr->addr1);
-	tx->fc = le16_to_cpu(hdr->frame_control);
 
 	/*
 	 * set defaults for things that can be set by
@@ -985,6 +983,8 @@
 		res = TXRX_QUEUED; /* indication it was monitor packet */
 	}
 
+	tx->sta = sta_info_get(local, hdr->addr1);
+	tx->fc = le16_to_cpu(hdr->frame_control);
 	tx->u.tx.control = control;
 	if (is_multicast_ether_addr(hdr->addr1)) {
 		tx->flags &= ~IEEE80211_TXRXD_TXUNICAST;