drivers/net/ethernet/broadcom/cnic.c: remove invalid reference to list iterator variable

If list_for_each_entry, etc complete a traversal of the list, the iterator
variable ends up pointing to an address at an offset from the list head,
and not a meaningful structure.  Thus this value should not be used after
the end of the iterator.  There does not seem to be a meaningful value to
provide to netdev_warn.  Replace with pr_warn, since pr_err is used
elsewhere.

This problem was found using Coccinelle (http://coccinelle.lip6.fr/).
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/cnic.c

@@ -534,7 +534,8 @@ int cnic_unregister_driver(int ulp_type)
 	}
 
 	if (atomic_read(&ulp_ops->ref_count) != 0)
-		netdev_warn(dev->netdev, "Failed waiting for ref count to go to zero\n");
+		pr_warn("%s: Failed waiting for ref count to go to zero\n",
+			__func__);
 	return 0;
 
 out_unlock: