Merge branch 'r8169-further-improvements'

Heiner Kallweit says:

====================
r8169: further improvements w/o functional change

This series aims at further improving and simplifying the code w/o
any intended functional changes.

Series was tested on: RTL8169sb, RTL8168d, RTL8168e-vl
====================

Signed-off-by: David S. Miller <davem@davemloft.net>