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: NTOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: NJia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>