Correct function name.

Modules/threadmodule.c

@@ -279,7 +279,7 @@ This is synonymous to ``raise SystemExit''.  It will cause the current\n\
 thread to exit silently unless the exception is caught.");
 
 static PyObject *
-sys_interrupt_main(PyObject * self, PyObject * args)
+thread_PyThread_interrupt_main(PyObject * self)
 {
 	PyErr_SetInterrupt();
 	Py_INCREF(Py_None);
@@ -290,7 +290,7 @@ PyDoc_STRVAR(interrupt_doc,
 "interrupt_main()\n\
 \n\
 Raise a KeyboardInterrupt in the main thread.\n\
-A subthread can use this method to interrupt the main thread."
+A subthread can use this function to interrupt the main thread."
 );
 
 #ifndef NO_EXIT_PROG
@@ -355,7 +355,7 @@ static PyMethodDef thread_methods[] = {
 	 METH_NOARGS, exit_doc},
 	{"exit",		(PyCFunction)thread_PyThread_exit_thread, 
 	 METH_NOARGS, exit_doc},
-	{"interrupt_main",	(PyCFunction)sys_interrupt_main,
+	{"interrupt_main",	(PyCFunction)thread_PyThread_interrupt_main,
 	 METH_NOARGS, interrupt_doc},
 	{"get_ident",		(PyCFunction)thread_get_ident, 
 	 METH_NOARGS, get_ident_doc},