Fix inconsistent #include style

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>
diff --git a/clients/resizor.c b/clients/resizor.c
index e48095f..ede9429 100644
--- a/clients/resizor.c
+++ b/clients/resizor.c
@@ -28,7 +28,7 @@
 #include <math.h>
 
 #include "wayland-util.h"
-#include "wayland-client.h"
+#include <wayland-client.h>
 
 #include "window.h"