tracing: Rename ftrace_get_offsets_##call() to trace_event_get_offsets_##call()

The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The function ftrace_get_offsets_##call()
is used to find the offset into dynamically allocated trace event fields
for printing. 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 e27b87e..43be3b0 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -485,7 +485,7 @@
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
-static inline notrace int ftrace_get_offsets_##call(			\
+static inline notrace int trace_event_get_offsets_##call(		\
 	struct trace_event_data_offsets_##call *__data_offsets, proto)	\
 {									\
 	int __data_size = 0;						\