Fix includes right throughout the Xserver tree:

change "foo.h" to <X11/foo.h> for core headers, e.g. X.h, Xpoll.h;
change "foo.h", "extensions/foo.h" and "X11/foo.h" to
    <X11/extensions/foo.h> for extension headers, e.g. Xv.h;
change "foo.[ch]" to <X11/Xtrans/foo.[ch]> for Xtrans files.

mi/mibstore.c

@@ -45,9 +45,9 @@ implied warranty.
 /* $XFree86: xc/programs/Xserver/mi/mibstore.c,v 1.10tsi Exp $ */
 
 #define NEED_EVENTS
-#include "X.h"
-#include "Xmd.h"
-#include "Xproto.h"
+#include <X11/X.h>
+#include <X11/Xmd.h>
+#include <X11/Xproto.h>
 #include "misc.h"
 #include "regionstr.h"
 #include "scrnintstr.h"