tracing: Kill destroy_preds() and destroy_file_preds()

destroy_preds() makes no sense.

The only caller, event_remove(), actually wants destroy_file_preds().
__trace_remove_event_call() does destroy_call_preds() which takes care
of call->filter.

And after the previous change we can simply remove destroy_preds() from
event_remove(), we are going to call remove_event_from_tracers() which
in turn calls remove_event_file_dir()->free_event_filter().

Link: http://lkml.kernel.org/p/20140715184813.GA20488@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

include/linux/ftrace_event.h

@@ -404,7 +404,6 @@ enum event_trigger_type {
 	ETT_EVENT_ENABLE	= (1 << 3),
 };
 
-extern void destroy_preds(struct ftrace_event_file *file);
 extern void destroy_call_preds(struct ftrace_event_call *call);
 extern int filter_match_preds(struct event_filter *filter, void *rec);
 

kernel/trace/trace_events.c

@@ -1621,7 +1621,6 @@ static void event_remove(struct ftrace_event_call *call)
 		if (file->event_call != call)
 			continue;
 		ftrace_event_enable_disable(file, 0);
-		destroy_preds(file);
 		/*
 		 * The do_for_each_event_file() is
 		 * a double loop. After finding the call for this

kernel/trace/trace_events_filter.c

@@ -810,26 +810,6 @@ void destroy_call_preds(struct ftrace_event_call *call)
 	call->filter = NULL;
 }
 
-static void destroy_file_preds(struct ftrace_event_file *file)
-{
-	__free_filter(file->filter);
-	file->filter = NULL;
-}
-
-/*
- * Called when destroying the ftrace_event_file.
- * The file is being freed, so we do not need to worry about
- * the file being currently used. This is for module code removing
- * the tracepoints from within it.
- */
-void destroy_preds(struct ftrace_event_file *file)
-{
-	if (file->event_call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
-		destroy_call_preds(file->event_call);
-	else
-		destroy_file_preds(file);
-}
-
 static struct event_filter *__alloc_filter(void)
 {
 	struct event_filter *filter;