r8169: speed up rtl_loop_wait

When testing I figured out that most operations signal finish even
before we trigger the first delay. Seems like PCI(e) access and
memory barriers typically add enough latency. Therefore move the
first delay after the first check.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>