Input: joystick - use str_off_on() helper in sw_connect()

Remove hard-coded strings by using the str_off_on() helper.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://lore.kernel.org/r/20241202154603.1193-2-thorsten.blum@linux.dev


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>