open() will never succeed, as we always return -ENODEV.  Fix this
obvious bug.

Thanks to Jouni Ryno for reporting it.
Reported-by: NJouni Ryno <Jouni.Ryno@fmi.fi>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>