tracing: Make filter_check_discard() local

Nothing outside of the tracing directory calls filter_check_discard() or
check_filter_check_discard(). They should not be called by modules. Move
their prototypes into the local tracing header and remove their
EXPORT_SYMBOL() macros.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -318,7 +318,6 @@ int filter_check_discard(struct trace_event_file *file, void *rec,
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(filter_check_discard);
 
 int call_filter_check_discard(struct trace_event_call *call, void *rec,
 			      struct ring_buffer *buffer,
@@ -332,7 +331,6 @@ int call_filter_check_discard(struct trace_event_call *call, void *rec,
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(call_filter_check_discard);
 
 static cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu)
 {

kernel/trace/trace.h

@@ -1065,6 +1065,12 @@ struct trace_subsystem_dir {
 	int				nr_events;
 };
 
+extern int filter_check_discard(struct trace_event_file *file, void *rec,
+				struct ring_buffer *buffer,
+				struct ring_buffer_event *event);
+extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
+				     struct ring_buffer *buffer,
+				     struct ring_buffer_event *event);
 /*
  * Helper function for event_trigger_unlock_commit{_regs}().
  * If there are event triggers attached to this event that requires