LU-12014 llite: check correct size in ll_dom_finish_open()

LU-12014 llite: check correct size in ll_dom_finish_open()

The check in ll_dom_finish_open() for data end shouldn't
use i_size for comparision because it may be not updated
yet with just returned data from server. Use size value in
mdt_body from reply for that check.

Signed-off-by: Mikhail Pershin <mpershin@whamcloud.com>
Change-Id: I1104fbbb0eb4633869b9bf2d1803ac3e84e3853d
Reviewed-on: https://review.whamcloud.com/33895
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>