Order members to ensure alignment

8 + 4 + 4 ensures 16 with 8 byte alignment, which means that
'data' is certain to be 8 byte aligned. 4 + 8 + 4 might result
in something else in some funky environment.

include/maxscale/buffer.h

@@ -105,8 +105,8 @@ struct buffer_object_st
  */
 typedef struct
 {
-    int32_t          refcount; /*< Reference count on the buffer */
     buffer_object_t *bufobj;   /*< List of objects referred to by GWBUF */
+    int32_t          refcount; /*< Reference count on the buffer */
     uint32_t         info;     /*< Info bits */
     unsigned char    data[1];  /*< Actual memory that was allocated */
 } SHARED_BUF;