- Add a locked variant of bce_ifmedia_upd() for use within the driver and   add missing locking to bce_ifmedia_upd(). - While I'm here, unexpand an instance of LIST_FOREACH().
- Add a locked variant of bce_ifmedia_upd() for use within the driver and
  add missing locking to bce_ifmedia_upd().
- While I'm here, unexpand an instance of LIST_FOREACH().

MFC after:	2 weeks
Reviewed by:	scottl

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase