Prevent ENODEV on a /dev/ttyUSBx, used as a USB-serial console.

From: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>