Fix typo

src/pl/plpython/plpy_resultobject.c

@@ -21,7 +21,7 @@ static PyObject *PLy_result_status(PyObject *self, PyObject *args);
 static Py_ssize_t PLy_result_length(PyObject *arg);
 static PyObject *PLy_result_item(PyObject *arg, Py_ssize_t idx);
 static PyObject *PLy_result_slice(PyObject *arg, Py_ssize_t lidx, Py_ssize_t hidx);
-static int	PLy_result_ass_slice(PyObject *rg, Py_ssize_t lidx, Py_ssize_t hidx, PyObject *slice);
+static int	PLy_result_ass_slice(PyObject *arg, Py_ssize_t lidx, Py_ssize_t hidx, PyObject *slice);
 static PyObject *PLy_result_subscript(PyObject *arg, PyObject *item);
 static int	PLy_result_ass_subscript(PyObject *self, PyObject *item, PyObject *value);