e1000e: Switch e1000e_up to void, drop code checking for error result

The function e1000e_up always returns 0.  As such we can convert it to a
void and just ignore the results.  This allows us to drop some code in a
couple spots as we no longer need to worry about non-zero return values.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>