openvswitch: Remove pkt_key from OVS_CB

OVS keeps pointer to packet key in skb->cb, but the packet key is
store on stack. This could make code bit tricky. So it is better to
get rid of the pointer.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>

diff --cc net/openvswitch/actions.c
Simple merge

diff --cc net/openvswitch/datapath.c
Simple merge

diff --cc net/openvswitch/datapath.h
Simple merge