net: openvswitch: select vport upcall portid directly

The commit 69c51582ff786 ("dpif-netlink: don't allocate per
thread netlink sockets"), in Open vSwitch ovs-vswitchd, has
changed the number of allocated sockets to just one per port
by moving the socket array from a per handler structure to
a per datapath one. In the kernel datapath, a vport will have
only one socket in most case, if so select it directly in
fast-path.

Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>