[3.14] gh-142595: Amend be5e0dc (fix NULL pointer dereference) (GH-142775) (#142788)

gh-142595: Amend be5e0dc (fix NULL pointer dereference) (GH-142775)
(cherry picked from commit 15a9762)

Co-authored-by: Sergey B Kirpichev <[email protected]>

Author: miss-islington

Modules/_decimal/_decimal.c

@@ -6040,8 +6040,9 @@ _decimal_exec(PyObject *m)
 
     /* DecimalTuple */
     ASSIGN_PTR(collections, PyImport_ImportModule("collections"));
-    obj = PyObject_CallMethod(collections, "namedtuple", "(ss)", "DecimalTuple",
-                              "sign digits exponent");
+    ASSIGN_PTR(obj, PyObject_CallMethod(collections, "namedtuple", "(ss)",
+                                        "DecimalTuple",
+                                        "sign digits exponent"));
     if (!PyType_Check(obj)) {
         PyErr_SetString(PyExc_TypeError,
                         "type is expected from namedtuple call");