Use a consistent style for enum braces

https://gitlab.gnome.org/GNOME/mutter/merge_requests/361

src/backends/meta-cursor-renderer.c

@@ -51,7 +51,8 @@ struct _MetaCursorRendererPrivate
 };
 typedef struct _MetaCursorRendererPrivate MetaCursorRendererPrivate;
 
-enum {
+enum
+{
   CURSOR_PAINTED,
   LAST_SIGNAL
 };