In panel_attach, if misc_register fails, we need to delete scan_timer,
which was setup in keypad_init->init_scan_timer.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>