Michał's previous patch missed this tty check to fix up the
class_find_device() arguments.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Cc: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>