Fix the module name in limited-api test

Signed-off-by: Michał Górny <mgorny@quansight.com>

Author: mgorny

tests/packages/limited-api/module.c

@@ -20,7 +20,7 @@ static PyMethodDef methods[] = {
 
 static struct PyModuleDef module = {
     PyModuleDef_HEAD_INIT,
-    "plat",
+    "module",
     NULL,
     -1,
     methods,