datapath: Fix an error handling path in 'ovs_nla_init_match_and_action()

Upstream commit:
commit 5829e62ac17a40ab08c1b905565604a4b5fa7af6
Author: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Date:   Mon Sep 11 21:56:20 2017 +0200

    openvswitch: Fix an error handling path in 'ovs_nla_init_match_and_action()'

    All other error handling paths in this function go through the 'error'
    label. This one should do the same.

    Fixes: 9cc9a5cb176c ("datapath: Avoid using stack larger than 1024.")
    Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
    Acked-by: Pravin B Shelar <pshelar@ovn.org>
    Signed-off-by: David S. Miller <davem@davemloft.net>

Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Fixes: 850c2a4 ("datapath: Avoid using stack larger than 1024.")
Signed-off-by: Greg Rose <gvrose8192@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>

datapath/datapath.c

@@ -1140,7 +1140,8 @@ static int ovs_nla_init_match_and_action(struct net *net,
 		if (!a[OVS_FLOW_ATTR_KEY]) {
 			OVS_NLERR(log,
 				  "Flow key attribute not present in set flow.");
-			return -EINVAL;
+			error = -EINVAL;
+			goto error;
 		}
 
 		*acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], key,