libertas: free sk_buff with kfree_skb

free sk_buff with kfree_skb, instead of kree
 
Signed-off-by: Sergio Luis <sergio@larces.uece.br>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/wireless/libertas/rx.c b/drivers/net/wireless/libertas/rx.c
index 5749f22..079e6aa 100644
--- a/drivers/net/wireless/libertas/rx.c
+++ b/drivers/net/wireless/libertas/rx.c
@@ -328,7 +328,7 @@
 		lbs_deb_rx("rx err: frame received with bad length\n");
 		priv->stats.rx_length_errors++;
 		ret = -EINVAL;
-		kfree(skb);
+		kfree_skb(skb);
 		goto done;
 	}