LU-14804 nodemap: do not return error for improper ACL

LU-14804 nodemap: do not return error for improper ACL

In nodemap_map_acl(), in case the ACL is incorrect, do nothing
and just return initial size to caller.

Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I26aba9ce43e4a8878bfa47e145b1b44cfff89403
Reviewed-on: https://review.whamcloud.com/44127
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>