ofproto-dpif: Look at the flow's ofproto when handling flow misses.

ofproto-dpif: Look at the flow's ofproto when handling flow misses.

When handling flow misses, an attempt is made to group identical packets
together.  Before the single datapath, each OpenFlow port number was
unique, so the flow_equal() function was sufficient to check whether
packets are identical.  With the single datapath, the OpenFlow port
numbers are shared across bridges, so packets that arrive at the same
time and are identical other than their ingress port were being serviced
by the same ofproto instance.  This commit changes the duplicate flow
finding function to take the ofproto into account.

Bug #14934

Signed-off-by: Justin Pettit <jpettit@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>