openvswitch: checking wrong variable in queue_userspace_packet()

"skb" is non-NULL here, for example we dereference it in skb_clone().
The intent was to test "nskb" which was just set.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 777716b..e66341e 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -321,7 +321,7 @@
 			return -ENOMEM;
 
 		nskb = __vlan_put_tag(nskb, vlan_tx_tag_get(nskb));
-		if (!skb)
+		if (!nskb)
 			return -ENOMEM;
 
 		nskb->vlan_tci = 0;