[PATCH] e1000: Fix invalid memory reference

Fix an invalid memory reference in the e1000 driver which would cause
kernel panic.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Cc: Jeb Cramer <cramerj@intel.com>
Cc: John Ronciak <john.ronciak@intel.com>
Cc: Ganesh Venkatesan <ganesh.venkatesan@intel.com>
Cc: Jeff Garzik <jgarzik@pobox.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>