dtoolutil: Fix misnamed include guard

dtool/src/dtoolutil/dSearchPath.h

@@ -11,8 +11,8 @@
  * @date 2000-07-01
  */
 
-#ifndef PANDASEARCHPATH_H
-#define PANDASEARCHPATH_H
+#ifndef DSEARCHPATH_H
+#define DSEARCHPATH_H
 
 #include "dtoolbase.h"