o Bug fix: ethtool SSET and NWAY we're broken when !netif_running.
o Cleanup: removed PPC code optimization - not needed.
o Bug fix: workaround for Dell Avalon system: change descriptor
  write-back policy to write back 16 bytes rather than 8 bytes.
o Bug fix: added mwb() to force memory transaction ordering on ia-64.
o Cleanup: misc. whitespace cleanup.