usb: typec: fusb302: Fix debugfs issue

Removing the "fusb302" debugfs directory when unloading
the driver. That allows the driver to be loaded more then
one time. The directory will not get actually removed until
it is empty, so only after the last instance has been
removed.

This fixes an issue where the driver can't be re-loaded if
it has been unloaded as the "fusb302" debugfs directory
already exists.

Fixes: 76f0c53d

 ("usb: typec: fusb302: Move out of staging")
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>