tracing: Rename (un)register_ftrace_event() to (un)register_trace_event()

The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The functions (un)register_ftrace_event() is
really about trace_events, and the name should be register_trace_event()
instead.

Also renamed ftrace_event_reg() to trace_event_reg() for the same reason.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
index 8ef2c40..4cbfe85 100644
--- a/kernel/trace/trace_output.h
+++ b/kernel/trace/trace_output.h
@@ -32,7 +32,7 @@
 trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry);
 
 /* used by module unregistering */
-extern int __unregister_ftrace_event(struct trace_event *event);
+extern int __unregister_trace_event(struct trace_event *event);
 extern struct rw_semaphore trace_event_sem;
 
 #define SEQ_PUT_FIELD(s, x)				\