qapi/introspect.py: remove _gen_variants helper

It is easier to give a name to all of the dictly-typed objects we pass
around in introspect.py by removing this helper, as it does not return
an object that has any knowable type by itself.

Inline it into its only caller instead.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-14-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

scripts/qapi/introspect.py

@@ -242,10 +242,6 @@ def _gen_member(self, member):
             obj['features'] = self._gen_features(member.features)
         return Annotated(obj, member.ifcond)
 
-    def _gen_variants(self, tag_name, variants):
-        return {'tag': tag_name,
-                'variants': [self._gen_variant(v) for v in variants]}
-
     def _gen_variant(self, variant):
         obj = {'case': variant.name, 'type': self._use_type(variant.type)}
         return Annotated(obj, variant.ifcond)
@@ -269,9 +265,8 @@ def visit_object_type_flat(self, name, info, ifcond, features,
                                members, variants):
         obj = {'members': [self._gen_member(m) for m in members]}
         if variants:
-            obj.update(self._gen_variants(variants.tag_member.name,
-                                          variants.variants))
-
+            obj['tag'] = variants.tag_member.name
+            obj['variants'] = [self._gen_variant(v) for v in variants.variants]
         self._gen_tree(name, 'object', obj, ifcond, features)
 
     def visit_alternate_type(self, name, info, ifcond, features, variants):