Return the module at the end of its init function.
"import _msi" used to raise a SystemError.
diff --git a/PC/_msi.c b/PC/_msi.c
index ec6c203..a55aeca 100644
--- a/PC/_msi.c
+++ b/PC/_msi.c
@@ -1065,5 +1065,5 @@
     if (!MSIError)
 	return NULL;
     PyModule_AddObject(m, "MSIError", MSIError);
-    return NULL;
+    return m;
 }