HID: hiddev: do cleanup in failure of opening a device

Undo what we did for opening before releasing the memory slice.

Reported-by: syzbot <syzbot+62a1e04fd3ec2abf099e@syzkaller.appspotmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
