staging/lustre: Add __user annotations in lnetselftest code

This fixes a bunch of sparse warnings.

There is no code change.

Signed-off-by: frank zago <fzago@cray.com>
Reviewed-on: http://review.whamcloud.com/11819
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5396


Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>