Fix typo in _PyMethodDef_RawFastCallKeywords error message (GH-13343)

diff --git a/Objects/call.c b/Objects/call.c
index 68f9e87..337ca81 100644
--- a/Objects/call.c
+++ b/Objects/call.c
@@ -701,7 +701,7 @@
 
     default:
         PyErr_SetString(PyExc_SystemError,
-                        "Bad call flags in _PyCFunction_FastCallKeywords. "
+                        "Bad call flags in _PyMethodDef_RawFastCallKeywords. "
                         "METH_OLDARGS is no longer supported!");
         goto exit;
     }