Move obtaining module

Author: encukou

Objects/typevarobject.c

@@ -2123,22 +2123,21 @@ typealias_new_impl(PyTypeObject *type, PyObject *name, PyObject *value,
         return NULL;
     }
 
-    PyObject *module = caller();
-    if (module == NULL) {
-        return NULL;
-    }
-
     if (qualname == NULL || qualname == Py_None) {
         // If qualname was not set directly, we use name instead.
         qualname = name;
     } else {
         if (!PyUnicode_Check(qualname)) {
             PyErr_SetString(PyExc_TypeError, "qualname must be a string");
-            Py_DECREF(module);
             return NULL;
         }
     }
 
+    PyObject *module = caller();
+    if (module == NULL) {
+        return NULL;
+    }
+
     PyObject *ta = (PyObject *)typealias_alloc(
         name, qualname, checked_params, NULL, value, module);
     Py_DECREF(module);