datapath: Drop parameters from execute_actions().

datapath: Drop parameters from execute_actions().

It's (almost) always easier to understand a function with fewer parameters,
so this removes the now-redundant sw_flow_key and actions parameters from
execute_actions(), since they can be found through OVS_CB(skb)->flow now.

This also necessarily moves loop detection into execute_actions().
Otherwise, the flow's actions could have changed between the time that the
loop was detected and the time that it was suppressed, which would mean
that the wrong (version of the) flow would get suppressed.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>