Instantiating the rmi4 SPI transport driver without an interrupt assigned
caused the driver to fail to load, but it does not clean up its transport
device registration. Result may be a crash at a later time, for example
when rebooting the system.

Fixes: 8d99758d ("Input: synaptics-rmi4 - add SPI transport driver")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>