pass constant pointers

And again, convert arguments to const.

src/tagTracker.c

@@ -106,7 +106,7 @@ void resetVisitedFlagsInTagTracker(int type)
 	}
 }
 
-void visitInTagTracker(int type, char *str)
+void visitInTagTracker(int type, const char *str)
 {
 	TreeIterator iter;