ath9k: remove driver ASSERT, just use BUG_ON()

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 6caef1b..3a2204d 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -59,7 +59,7 @@
 
 	/* virtual addr of the beginning of the buffer. */
 	skb = bf->bf_mpdu;
-	ASSERT(skb != NULL);
+	BUG_ON(skb == NULL);
 	ds->ds_vdata = skb->data;
 
 	/* setup rx descriptors. The rx.bufsize here tells the harware