LU-6024 nodemap: fix ACL handling in mdt_finish_open

LU-6024 nodemap: fix ACL handling in mdt_finish_open

This patch adds ACL mapping code to mdt_finish_open so that clients
get a correctly mapped list. The code is essentially the same as in
mdt_getattr_internal.

Signed-off-by: Kit Westneat <kit.westneat@gmail.com>
Change-Id: I3cf0ba2128ba8c4027359329f423d2327005f082
Reviewed-on: http://review.whamcloud.com/13062
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Reviewed-by: Andrew Perepechko <andrew.perepechko@seagate.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>