LU-9183 llite: handle removal the pos argument of generic_write_sync

LU-9183 llite: handle removal the pos argument of generic_write_sync

In commit e259221763a40403d5bb232209998e8c45804ab8 the pos argument
of generic_write_sync() was removed.

Change-Id: Iad76c517e372d7dc5e12670b5a0b8106005b71ff
Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-on: https://review.whamcloud.com/25826
Tested-by: Jenkins
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>