CORD-2931 fix ValidationError;
eliminate requirement that slice names are prefixed by site

Change-Id: If8ad902302e442c4f2566713b7af556d284dd9cd
diff --git a/lib/xos-genx/xosgenx/jinja2_extensions/fol2.py b/lib/xos-genx/xosgenx/jinja2_extensions/fol2.py
index 3042e37..73d04af 100644
--- a/lib/xos-genx/xosgenx/jinja2_extensions/fol2.py
+++ b/lib/xos-genx/xosgenx/jinja2_extensions/fol2.py
@@ -423,7 +423,7 @@
         self.verdict_next()
         function_str = """
 def %(fn_name)s(obj, ctx):
-    if not %(vvar)s: raise ValidationError("%(message)s".format(obj=obj, ctx=ctx))
+    if not %(vvar)s: raise XOSValidationError("%(message)s".format(obj=obj, ctx=ctx))
         """ % {'fn_name': policy_function_name, 'vvar': self.verdict_variable, 'message': message}
 
         function_ast = self.str_to_ast(function_str)