Part of this upstream commit:

commit cb17f478bb102bc437976046ac9d39182aa758aa
Author: Ross Burton <ross.burton@intel.com>
Date:   Mon Dec 10 11:33:32 2012 +0000

    Remove some unused variables

diff --git a/libmb/mbpixbuf.c b/libmb/mbpixbuf.c
index 3811d0874b19fa47..f0da64b0a8aa221d 100644
--- a/libmb/mbpixbuf.c
+++ b/libmb/mbpixbuf.c
@@ -22,6 +22,7 @@
 
 #include <strings.h>
 #include "mbpixbuf.h"
+#include "mbutil.h"
 
 #define BYTE_ORD_24_RGB  0
 #define BYTE_ORD_24_RBG  1