Changing an inode's metadata may result in our not needing to appraise
the file.  In such cases, we must remove 'security.ima'.

Changelog v1:
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>