[TULIP]: NAPI full quantum bug.

This should fix the kernel warn/oops reported while routing.

The tulip driver has a fencepost bug with new NAPI in 2.6.24
It has an off by one bug if a full quantum is reached.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>