Avoid useless typecodes error check

Author: mpaolini

Modules/arraymodule.c

@@ -3059,11 +3059,8 @@ array_modexec(PyObject *m)
         *p++ = (char)descr->typecode;
     }
     typecodes = PyUnicode_DecodeASCII(buffer, p - buffer, NULL);
-    if (typecodes == NULL) {
-        return -1;
-    }
     if (PyModule_AddObject(m, "typecodes", typecodes) < 0) {
-        Py_DECREF(typecodes);
+        Py_XDECREF(typecodes);
         return -1;
     }