net: sched: extract common action counters update code into function

[ Upstream commit c8ecebd04cbb6badb46d42fe54282e7883ed63cc ]

Currently, all implementations of tc_action_ops->stats_update() callback
have almost exactly the same implementation of counters update
code (besides gact which also updates drop counter). In order to simplify
support for using both percpu-allocated and regular action counters
depending on run-time flag in following patches, extract action counters
update code into standalone function in act API.

This commit doesn't change functionality.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: ca22da2fbd69 ("act_mirred: use the backlog for nested calls to mirred ingress")
Signed-off-by: Shubham Kulkarni <skulkarni@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>