e1000e: Drop unnecessary __E1000_DOWN bit twiddling

Since we no longer check for __E1000_DOWN in e1000e_close we can drop the
spot where we were restoring the bit. This saves us a bit of unnecessary
complexity.

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