Remove the last stray reference to the old name

(thanks cole-h)

 include/render.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/render.h b/include/render.h
index a466474..cfbd1df 100644
--- a/include/render.h
+++ b/include/render.h
@@ -1,5 +1,5 @@
-#ifndef ZAG_RENDER_H
-#define ZAG_RENDER_H
+#ifndef RIVER_RENDER_H
+#define RIVER_RENDER_H
 
 #include <wlr/backend/session.h>
 /*