LU-7623 Update obd iocontrol methods with __user attribute

lmv_iocontrol, osc_iocontrol, mdt_iocontrol, mgs_iocontrol, ofd_iocontrol,
osc_iocontrol, osp_iocontrol and echo_client_brw_ioctl were somehow missing
the __user attribute for uarg.

Change-Id: I10603823f5856fee6ca48c2aea03273e9d29144e
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: http://review.whamcloud.com/17781
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>