Merge tag 'usb-serial-4.17-rc4' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-linus

Johan writes:

USB-serial fixes for v4.17-rc4

Here's a fix for a long-standing issue in the visor driver, which could
have security implications. Included is also a new modem device id.

Both commits have been in linux-next for a couple of days with no
reported issues.

Signed-off-by: Johan Hovold <johan@kernel.org>