remove warning on MacOS X.

git-svn-id: http://root.cern.ch/svn/root/trunk@7211 27541ba8-7e3a-0410-8455-c3a389f83636

build/rmkdepend/ifparser.h

@@ -61,6 +61,9 @@
 
 #include <stdio.h>
 
+#ifdef const
+#undef const
+#endif
 #define const /**/
 typedef int Bool;
 #define False 0