tracing: ftrace_event_is_function() can return boolean

Make ftrace_event_is_function() return bool to improve readability
due to this particular function only using either one or zero as its
return value.

No functional change.

Link: http://lkml.kernel.org/r/1443537816-5788-9-git-send-email-bywxiaobai@163.comSigned-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace.h

@@ -873,7 +873,7 @@ void ftrace_destroy_filter_files(struct ftrace_ops *ops);
 #define ftrace_destroy_filter_files(ops) do { } while (0)
 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
 
-int ftrace_event_is_function(struct trace_event_call *call);
+bool ftrace_event_is_function(struct trace_event_call *call);
 
 /*
  * struct trace_parser - servers for reading the user input separated by spaces

kernel/trace/trace_export.c

@@ -187,7 +187,7 @@ __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call;
 	FTRACE_ENTRY_REG(call, struct_name, etype,			\
 			 PARAMS(tstruct), PARAMS(print), filter, NULL)
 
-int ftrace_event_is_function(struct trace_event_call *call)
+bool ftrace_event_is_function(struct trace_event_call *call)
 {
 	return call == &event_function;
 }