LU-1346 libcfs: replace libcfs wrappers with kernel API

LU-1346 libcfs: replace libcfs wrappers with kernel API

The libcfs kernel portability library had wrappers for many low-level
kernel functions (locking, bit operations, etc) that were simple
wrappers around Linux kernel functions.  This provides no value for
Linux clients and clients for other kernels are not under development.

Remove the cfs_ prefix from these simple wrapper functions.  For other
kernels, they will need to use the Linux kernel API for portability.

Affected primitives:
spinlock_t, spin_lock_init, spin_lock, spin_unlock, spin_lock_bh,
spin_lock_bh_init, spin_unlock_bh, spin_trylock, spin_is_locked,
spin_lock_irq, spin_unlock_irq, read_lock_irqsave, write_lock_irqsave,
read_lock_irqrestore, write_lock_irqrestore, spin_lock_irqsave,
spin_unlock_irqrestore, SPIN_LOCK_UNLOCKED

rw_semaphore, init_rwsem, down_read, down_read_trylock, up_read,
down_write, down_write_trylock, up_write, fini_rwsem, DECLARE_RWSEM

semaphore, rw_semaphore, init_completion_module, call_wait_handler,
wait_handler_t, mt_completion_t, mt_init_completion,
mt_wait_for_completion, mt_complete, mt_fini_completion, mt_atomic_t,
mt_atomic_read, mt_atomic_set, mt_atomic_dec_and_test, mt_atomic_inc,
mt_atomic_dec, mt_atomic_add, mt_atomic_sub

rw_lock_t, rwlock_init, read_lock, read_unlock,
read_unlock_irqrestore, write_lock, write_unlock, write_lock_bh,
write_unlock_bh, RW_LOCK_UNLOCKED

completion_t, DECLARE_COMPLETION, INIT_COMPLETION, complete,
COMPLETION_INITIALIZER, init_completion, wait_for_completion,
wait_for_completion_interruptible, complete_and_exit, fini_completion

semaphore_t, DEFINE_SEMAPHORE, sema_init, up, down,
down_interruptible, down_trylock

mutex_t, DEFINE_MUTEX, mutex_init, mutex_lock, mutex_unlock,
mutex_lock_interruptible, mutex_trylock, mutex_is_locked,
mutex_destroy

lock_kernel, unlock_kernel

lock_class_key, lock_class_key_t, lockdep_set_class, lockdep_off,
lockdep_on, mutext_lock_nexted, spin_lock_nexted, down_read_nested,
down_write_nested

test_bit, set_bit, clear_bit, test_and_set_bit, test_and_clear_bit,
find_first_bit, find_first_zero_bit, find_next_bit,
find_next_zero_bit, ffz, ffs, fls

Change-Id: I36db204c703ed414504eaa9ba22e97ad7eb6cc2c
Signed-off-by: Liu Xuezhao <xuezhao.liu@emc.com>
Signed-off-by: Oleg Drokin <green@whamcloud.com>
Reviewed-on: http://review.whamcloud.com/2829
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>