e1000e: remove unnecessary returns from void functions

...and convert some goto's which simply return to just return.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --cc drivers/net/ethernet/intel/e1000e/ich8lan.c
Simple merge

diff --cc drivers/net/ethernet/intel/e1000e/mac.c
Simple merge

diff --cc drivers/net/ethernet/intel/e1000e/netdev.c
Simple merge