HID: alps: fix error return code in alps_input_configured()

When input_register_device() fails, no error return code is assigned.
To fix this bug, ret is assigned with -ENOENT as error return code.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>