LU-11919 llite: Initialize cl_dirty_max_pages

LU-11919 llite: Initialize cl_dirty_max_pages

cl_dirty_max_pages must be initialized to zero before
calling client_adjust_max_dirty.

Test-Parameters: trivial

Signed-off-by: Patrick Farrell <pfarrell@whamcloud.com>
Change-Id: Ie34306ae329e377520a7a4858ab969f901c6154d
Reviewed-on: https://review.whamcloud.com/34173
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Li Xi <lixi@ddn.com>