Make control_write_reply() mockable

Part of ticket 30889.

src/feature/control/control_proto.c

@@ -176,8 +176,9 @@ send_control_done(control_connection_t *conn)
  * @param c separator character, usually ' ', '-', or '+'
  * @param s string
  */
-void
-control_write_reply(control_connection_t *conn, int code, int c, const char *s)
+MOCK_IMPL(void,
+control_write_reply, (control_connection_t *conn, int code, int c,
+                      const char *s))
 {
   connection_printf_to_buf(conn, "%03d%c%s\r\n", code, c, s);
 }

src/feature/control/control_proto.h

@@ -21,8 +21,8 @@ size_t write_escaped_data(const char *data, size_t len, char **out);
 size_t read_escaped_data(const char *data, size_t len, char **out);
 void send_control_done(control_connection_t *conn);
 
-void control_write_reply(control_connection_t *conn, int code, int c,
-                         const char *s);
+MOCK_DECL(void, control_write_reply, (control_connection_t *conn, int code,
+                                      int c, const char *s));
 void control_vprintf_reply(control_connection_t *conn, int code, int c,
                            const char *fmt, va_list ap)
   CHECK_PRINTF(4, 0);