openvswitch: Fix double-free on ip_defrag() errors

openvswitch: Fix double-free on ip_defrag() errors

If ip_defrag() returns an error other than -EINPROGRESS, then the skb is
freed. When handle_fragments() passes this back up to
do_execute_actions(), it will be freed again. Prevent this double free
by never freeing the skb in do_execute_actions() for errors returned by
ovs_ct_execute. Always free it in ovs_ct_execute() error paths instead.

Fixes: 7f8a436eaa2c ("openvswitch: Add conntrack action")
Reported-by: Florian Westphal <[email protected]>
Signed-off-by: Joe Stringer <[email protected]>
Acked-by: Pravin B Shelar <[email protected]>
Signed-off-by: David S. Miller <[email protected]>