ath9k: Free Beacon skbs in AP mode

Fix a memory leak where AP mode did not free transmitted Beacon frame
skbs.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Acked-by: Pat Erley <pat-lkml@erley.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath9k/beacon.c b/drivers/net/wireless/ath9k/beacon.c
index 507299b..d874223 100644
--- a/drivers/net/wireless/ath9k/beacon.c
+++ b/drivers/net/wireless/ath9k/beacon.c
@@ -167,6 +167,7 @@
 		pci_unmap_single(sc->pdev, bf->bf_dmacontext,
 				 skb->len,
 				 PCI_DMA_TODEVICE);
+		dev_kfree_skb_any(skb);
 	}
 
 	skb = ieee80211_beacon_get(sc->hw, vif);