commit 755ac67f upstream.

If the acl can be exactly represented in the traditional file
mode permission bits, we don't set another acl attribute.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>