Simplify PyUnicode_FSConverter(): remove reference to PyByteArray

PyByteArray is no more supported

Objects/unicodeobject.c

@@ -1638,7 +1638,7 @@ PyUnicode_FSConverter(PyObject* arg, void* addr)
         arg = PyUnicode_FromObject(arg);
         if (!arg)
             return 0;
-        output = PyUnicode_AsEncodedObject(arg, 
+        output = PyUnicode_AsEncodedObject(arg,
                                            Py_FileSystemDefaultEncoding,
                                            "surrogateescape");
         Py_DECREF(arg);
@@ -1650,14 +1650,8 @@ PyUnicode_FSConverter(PyObject* arg, void* addr)
             return 0;
         }
     }
-    if (PyBytes_Check(output)) {
-         size = PyBytes_GET_SIZE(output);
-         data = PyBytes_AS_STRING(output);
-    } 
-    else {
-         size = PyByteArray_GET_SIZE(output);
-         data = PyByteArray_AS_STRING(output);
-    }
+    size = PyBytes_GET_SIZE(output);
+    data = PyBytes_AS_STRING(output);
     if (size != strlen(data)) {
         PyErr_SetString(PyExc_TypeError, "embedded NUL character");
         Py_DECREF(output);