fix format string

Index: bochs/cpu/apic.cc
--- bochs/cpu/apic.cc.orig
+++ bochs/cpu/apic.cc
@@ -32,6 +32,8 @@
 #include "pc_system.h"
 #include "iodev/iodev.h"
 
+#include <inttypes.h>
+
 extern bool simulate_xapic;
 
 #define LOG_THIS this->
