log.h: Supply missing includes

<stdio.h> has always been missing.  Rest missed in commit eeacee4d.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NLaszlo "ever the optimist" Ersek <lersek@redhat.com>
Message-id: 1370610036-10577-3-git-send-email-armbru@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

include/qemu/log.h

@@ -2,6 +2,9 @@
 #define QEMU_LOG_H
 
 #include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include "qemu/compiler.h"
 #ifdef NEED_CPU_H
 #include "disas/disas.h"
 #endif