Fix bug #10010 - Missing integer wrap protection in EA list reading can cause server to loop with DOS.

Ensure we never wrap whilst adding client provided input.
CVE-2013-4124

Signed-off-by: Jeremy Allison <jra@samba.org>
WHATSNEW: Add release notes for Samba 3.5.22.

Signed-off-by: Karolin Seeger <kseeger@samba.org>