markers/tracpoints: fix non-modular build

fix:

 kernel/marker.c: In function 'marker_module_notify':
 kernel/marker.c:905: error: 'MODULE_STATE_COMING' undeclared (first use in this function)
 [...]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 94ac4e3..7960274 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -542,6 +542,8 @@
 }
 EXPORT_SYMBOL_GPL(tracepoint_iter_reset);
 
+#ifdef CONFIG_MODULES
+
 int tracepoint_module_notify(struct notifier_block *self,
 			     unsigned long val, void *data)
 {
@@ -570,3 +572,5 @@
 	return register_module_notifier(&tracepoint_module_nb);
 }
 __initcall(init_tracepoints);
+
+#endif /* CONFIG_MODULES */