HID: ACRUX - add missing hid_hw_stop() in ax_probe() error path

hid_hw_stop() must be called in ax_probe() error path if hid_hw_start()
was successful.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>