ftrace: fix building with SYSCTL=y but DYNAMIC_FTRACE=n

Ok so hopefully this is the last of it. 0day picked up a build
failure [0] when SYSCTL=y but DYNAMIC_FTRACE=n. This can be fixed
by just declaring an empty routine for the calls moved just
recently.

[0] https://lkml.kernel.org/r/202204161203.6dSlgKJX-lkp@intel.com

Reported-by: kernel test robot <lkp@intel.com>
Fixes: f8b7d2b ("ftrace: fix building with SYSCTL=n but DYNAMIC_FTRACE=y")
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

Author: mcgrof

kernel/trace/ftrace.c

@@ -7873,6 +7873,8 @@ int unregister_ftrace_function(struct ftrace_ops *ops)
 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
 
 #ifdef CONFIG_SYSCTL
+
+#ifdef CONFIG_DYNAMIC_FTRACE
 static void ftrace_startup_sysctl(void)
 {
 	int command;
@@ -7906,6 +7908,10 @@ static void ftrace_shutdown_sysctl(void)
 		ftrace_run_update_code(command);
 	}
 }
+#else
+# define ftrace_startup_sysctl()       do { } while (0)
+# define ftrace_shutdown_sysctl()      do { } while (0)
+#endif /* CONFIG_DYNAMIC_FTRACE */
 
 static bool is_permanent_ops_registered(void)
 {