LU-823 compat: Don't use cfs_ functions on kernel structures

LU-823 compat: Don't use cfs_ functions on kernel structures

It is not really correct to use the generic "cfs_" prefixed
locking functions on the Linux kernel's data structures.  Revert
back to using the Linux locking function.

Change-Id: I64619c4b4f4963634b3d1e43c1b1519598e65e8d
Signed-off-by: Christopher J. Morrone <morrone2@llnl.gov>
Reviewed-on: http://review.whamcloud.com/4176
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Keith Mannthey <keith.mannthey@intel.com>
Reviewed-by: Peng Tao <bergwolf@gmail.com>