LU-4423 ptlrpc: Fix function prototypes

LU-4423 ptlrpc: Fix function prototypes

ptlrpc_request_cache_init and ptlrpc_request_cache_fini
added by request cache code did not include argument type
in the declaration which causes a checkpatch warning.

Change-Id: I41f4f96cfbc9e63417b6adbe6ba1902248494fbb
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: http://review.whamcloud.com/10120
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>