Fix sparse warnings and problems from e1000 driver.

Added a sparse fix for the module param array index
-- Auke
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NAuke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>