Rename exts stats update functions with hw for readability.

We make this change also to update stats from hw for an action
when it is offloaded to hw as a single action.
Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>