LU-5396: ni: make local functions static

LU-5396: ni: make local functions static

This reduces the code size by about 400 bytes.

Change-Id: I158c3b2c5c68f92938c29090faab1c0153d19e2e
Signed-off-by: frank zago <fzago@cray.com>
Reviewed-on: http://review.whamcloud.com/11306
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Patrick Farrell <paf@cray.com>
Reviewed-by: Amir Shehata <amir.shehata@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>