LU-4703 mdd: do not skip xattr sanity check for all cases

xattr sanity check should be done at all times.
Otherwise we are risking letting a non root user setting
access acl on any file.

Lustre-commit: 6d7066989c06bdf6c86f5b8b61d542fda8e5739e
Lustre-change: http://review.whamcloud.com/9469

Signed-off-by: Li Dongyang <dongyang.li@anu.edu.au>
Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Change-Id: Ic763424b2a20dab00c7e62de1f5c8553cd0cdaa8
LU-4704 acl: fix permission problem of setfacl

Setxattr does not check the permission when setting ACL xattrs. This
will cause security problem because any user can walk around
permission checking by changing ACL rules.

Lustre-commit: 42f504ecada81d7a2a8e2244f345e8dbf73fd157
Lustre-change: http://review.whamcloud.com/9473

Signed-off-by: Li Xi <lixi@ddn.com>
Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Emoly Liu <emoly.liu@intel.com>
Change-Id: I5844c5b654afd70fb3b5ee91c024736b377124b0