staging/lustre/obd: remove struct client_obd_lock

Remove the definition of struct client_obd_lock and the functions
client_obd_list_{init,lock,unlock,done}(). Use spinlock_t for the
cl_{loi,lru}_list_lock members of struct client_obd and call
spin_{lock,unlock}() directly.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>