Revert "e1000: fix NAPI performance on 4-port adapters"

This reverts commit 60cba200

.  It's been
linked to lockups of the e1000 hardware, see for example

	https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=229603

but it's likely that the commit itself is not really introducing the
bug, but just allowing an unrelated problem to rear its ugly head (ie
one current working theory is that the code exposes us to a hardware
race condition by decreasing the amount of time we spend in each NAPI
poll cycle).

We'll revert it until root cause is known.  Intel has a repeatable
reproduction on two different machines and bus traces of the hardware
doing something bad.

Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Greg KH <gregkh@suse.de>
Cc: Dave Jones <davej@redhat.com>
Cc: Auke Kok <auke-jan.h.kok@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>