Extcon: Don't try to create duplicate link names

We can't create a link from the device to the compatibility switch class
since we already create a link from the device to to the extcon class
object and we try to use the same name for both links. This causes a loud
complaint from sysfs on boot.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>