Fixed number of callbacks, added prototype of function to set

callback. Nothing important.

vfs/callback.h

@@ -1,9 +1,17 @@
+#ifndef CALLBACK_H
+#define CALLBACK_H
+
 /* 
- * Warning: there's better version of this file somewhere else.
+ * All callbacks are char *func( char *msg );
+ * INFO/BOX should always return NULL;
  */
 
 #define CALL_INFO 0
 #define CALL_BOX 1
 #define CALL_PASSWD 2
 
-#define NUM_CALLBACKS 4
+#define NUM_CALLBACKS 3
+
+extern void vfs_set_callback( int num, void *func );
+
+#endif