lib: Retire packet buffering feature.

lib: Retire packet buffering feature.

OVS implementation of buffering packets that are sent to the
controller is not compliant with the OpenFlow specifications after
OpenFlow 1.0, which is possibly true since OpenFlow 1.0 is not really
specifying the packet buffering behavior.

OVS implementation executes the buffered packet against the actions of
the modified or added rule, whereas OpenFlow (since 1.1) specifies
that the packet should be matched against the flow table 0 and
processed accordingly.

Rather than fix this behavior, and potentially break OVS users, the
packet buffering feature is removed altogether.  After all, such
packet buffering is an optional OpenFlow feature, and as such any
possible users should continue to work without this feature.

This patch also makes OVS check the received 'buffer_id' values more
rigorously, and fixes some internal users accordingly.

Found by inspection.

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