tracing: Rename ftrace_data_offset_##call to trace_event_data_offset_##call

The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The structure ftrace_data_offset_##call is
used to find the offsets of dynamically allocated fields in trace_events.
It has nothing to do with function tracing. Rename it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 0e9519d..18c7c02 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -138,7 +138,7 @@
  *
  * Include the following:
  *
- * struct ftrace_data_offsets_<call> {
+ * struct trace_event_data_offsets_<call> {
  *	u32				<item1>;
  *	u32				<item2>;
  *	[...]
@@ -178,7 +178,7 @@
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
-	struct ftrace_data_offsets_##call {				\
+	struct trace_event_data_offsets_##call {			\
 		tstruct;						\
 	};
 
@@ -486,7 +486,7 @@
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
 static inline notrace int ftrace_get_offsets_##call(			\
-	struct ftrace_data_offsets_##call *__data_offsets, proto)       \
+	struct trace_event_data_offsets_##call *__data_offsets, proto)	\
 {									\
 	int __data_size = 0;						\
 	int __maybe_unused __item_length;				\