LU-12383 utils: only check project inherit bit for dir

LU-12383 utils: only check project inherit bit for dir

Currently, ZFS won't set inherit bit on regular files, but
ext4 always set it, it doesn't make sense for regular files
have this bit, but own it won't do any harm as well.

To make test happy and give a consistent view on users,
let's fix project check only complain erros for Direcotry.

Lustre-change: https://review.whamcloud.com/35076
Lustre-commit: e4ad5c17c99e7ede5deabffe0bacdd851240eb86

Test-Parameters: trivial testlist=sanity-quota
Change-Id: I194f3ed9d6ded69313a683995295ab8c07b4fb3a
Signed-off-by: Wang Shilong <wshilong@ddn.com>
Reviewed-by: Nathaniel Clark <nclark@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/35393
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>