staging/lustre: remove lots of dead code

This is a large patch to remove all dead code from obdclass and
ptlrpc, purely removing functions and declarations now, so
despite the size should be easy enough to verify.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>