Fix #11586: typo in initfsencoding()

Patch written by Ray Allen.
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 8e97d7f..38b2ab8 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -147,7 +147,7 @@
         goto error;
 
     name_utf8 = _PyUnicode_AsString(name);
-    if (name == NULL)
+    if (name_utf8 == NULL)
         goto error;
     name_str = strdup(name_utf8);
     Py_DECREF(name);