LU-2675 obd: remove client_obd_lock_t

LU-2675 obd: remove client_obd_lock_t

Remove the definition of client_obd_lock_t 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>
Change-Id: I3c4b9cf531b6d62c3481a40f4a1c448cf864beec
Reviewed-on: http://review.whamcloud.com/12231
Tested-by: Jenkins
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>