LU-5396 mdc: add sparse annotation __user wherever needed

LU-5396 mdc: add sparse annotation __user wherever needed

This fixes sparse warnings such as:

  .../api-ni.c:1639:33: warning: incorrect type in argument 3
                             (different address spaces)
  .../api-ni.c:1639:33:    expected struct lnet_process_id_t
                             [noderef] [usertype] <asn:1>*ids
  .../api-ni.c:1639:33:    got struct lnet_process_id_t
                             [usertype] *<noident>

There is no code change.

Change-Id: Ie3acf675d284a595d4aa871b522a0c409973da18
Signed-off-by: frank zago <fzago@cray.com>
Reviewed-on: http://review.whamcloud.com/11822
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>