r8169: add support for xmit_more
r8169: add support for xmit_more

Delay update of hw tail descriptor if we know that another skb is going
to be sent.

Signed-off-by: Florian Westphal <cef439e78636cdab99cd2923826c5065a0743e5b@strlen.de>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs