trace-cmd: Fix warning for undeclared function trace_util_ftrace_options

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/trace-cmd.h b/trace-cmd.h
index f436845..fc3e9d1 100644
--- a/trace-cmd.h
+++ b/trace-cmd.h
@@ -186,6 +186,7 @@
 struct tracecmd_output *tracecmd_create_init_file_override(const char *output_file,
 							   const char *tracing_dir,
 							   const char *kallsyms);
+void trace_util_ftrace_options(void);
 int tracecmd_add_option(struct tracecmd_output *handle,
 			unsigned short id,
 			int size, void *data);