tracing: Remove obsolete macro guard _TRACE_PROFILE_INIT

The macro _TRACE_PROFILE_INIT was removed a long time ago,
but an "#undef" guard was left behind. Remove it.

Link: http://lkml.kernel.org/r/514684EE.6000805@huawei.com

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 4bda044..19edd7f 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -704,5 +704,3 @@
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 #endif /* CONFIG_PERF_EVENTS */
 
-#undef _TRACE_PROFILE_INIT
-