[mutter] output/xrandr: Fix include guards

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 6697b0d069b6664ad668f53ac449786dca04672a
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Feb 26 11:05:58 2020 +0100

    output/xrandr: Fix include guards
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1287

 src/backends/x11/meta-output-xrandr.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/backends/x11/meta-output-xrandr.h b/src/backends/x11/meta-output-xrandr.h
index 6c97b84865..1f4c517707 100644
--- a/src/backends/x11/meta-output-xrandr.h
+++ b/src/backends/x11/meta-output-xrandr.h
@@ -19,8 +19,8 @@
  * 02111-1307, USA.
  */
 
-#ifndef META_OUTPUT_XRANDR
-#define META_OUTPUT_XRANDR
+#ifndef META_OUTPUT_XRANDR_H
+#define META_OUTPUT_XRANDR_H
 
 #include <X11/extensions/Xrandr.h>
 
@@ -40,4 +40,4 @@ MetaOutput * meta_create_xrandr_output (MetaGpuXrandr *gpu_xrandr,
                                         RROutput       output_id,
                                         RROutput       primary_output);
 
-#endif /* META_OUTPUT_XRANDR */
+#endif /* META_OUTPUT_XRANDR_H */