conf: use fd_cloexec()

src/lxc/conf.c

@@ -984,12 +984,12 @@ int lxc_allocate_ttys(struct lxc_conf *conf)
 		      tty->name, tty->master, tty->slave);
 
 		/* Prevent leaking the file descriptors to the container */
-		ret = fcntl(tty->master, F_SETFD, FD_CLOEXEC);
+		ret = fd_cloexec(tty->master, true);
 		if (ret < 0)
 			SYSWARN("Failed to set FD_CLOEXEC flag on master fd %d of "
 			        "tty device \"%s\"", tty->master, tty->name);
 
-		ret = fcntl(tty->slave, F_SETFD, FD_CLOEXEC);
+		ret = fd_cloexec(tty->slave, true);
 		if (ret < 0)
 			SYSWARN("Failed to set FD_CLOEXEC flag on slave fd %d of "
 			        "tty device \"%s\"", tty->slave, tty->name);