ofproto-dpif-xlate: Do not execute resubmit again after recirculation.

ofproto-dpif-xlate: Do not execute resubmit again after recirculation.

Consider the following flow table:

    table=0 actions=resubmit(,1),2
    table=1 actions=debug_recirc

When debug_recirc triggers recirculation and we later resume processing,
only the output to port 2 should be executed, because the effects of
"resubmit" have already taken place.  However, until now, the "resubmit"
was added to the actions to execute post-recirculation, resulting in an
infinite loop.

Now consider this flow table (as seen in the "MPLS handling" test in
ofproto-dpif.at):

    table=0 actions=pop_mpls(0x0806),resubmit(,1)
    table=1 ip,nw_dst=1.2.3.4 actions=controller

Here, we do want to add the "resubmit" to the actions to execute
post-recirculation, since the "resubmit" cannot be processed until after
recirculation makes the nw_dst field available.

This commit fixes the problem in both cases.

Found when testing a feature based on recirculation.

Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Jarno Rajahalme <jarno@ovn.org>