ftrace: rename the ftrace tracer to function

To avoid further confusion between the ftrace infrastructure and the
function tracer. This patch renames the "ftrace" function tracer
to "function".

Now in available_tracers, instead of "ftrace" there will be "function".

This makes more sense, since people will not know exactly what the
"ftrace" tracer does.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/trace/trace_functions.c

@@ -64,7 +64,7 @@ static void function_trace_ctrl_update(struct trace_array *tr)
 
 static struct tracer function_trace __read_mostly =
 {
-	.name	     = "ftrace",
+	.name	     = "function",
 	.init	     = function_trace_init,
 	.reset	     = function_trace_reset,
 	.ctrl_update = function_trace_ctrl_update,