e1000: fix adapter led blinking inconsistency

Several e1000 adapters were not blinking correctly or inconsistently. This
patch cleans this up and makes them all behave the same as far as possible.

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>