Add additional checks for attributes

Some decorators (like dtt) do have a func attribute
but no "attr" and "value" attribute defined.
This leads to errors during pep8 gate check (see [1]).

[1]: https://review.openstack.org/#/c/153234/4

Closes-Bug: #1431267
Change-Id: Id16bce40e30ecb6bc5bff9b55650acc538ece3a9
diff --git a/tools/check_uuid.py b/tools/check_uuid.py
index 541e6c3..ebbdc78 100644
--- a/tools/check_uuid.py
+++ b/tools/check_uuid.py
@@ -119,8 +119,10 @@
         idempotent_id = None
         for decorator in test_node.decorator_list:
             if (hasattr(decorator, 'func') and
-                    decorator.func.attr == DECORATOR_NAME and
-                    decorator.func.value.id == DECORATOR_MODULE):
+                hasattr(decorator.func, 'attr') and
+                decorator.func.attr == DECORATOR_NAME and
+                hasattr(decorator.func, 'value') and
+                decorator.func.value.id == DECORATOR_MODULE):
                 for arg in decorator.args:
                     idempotent_id = ast.literal_eval(arg)
         return idempotent_id