HID: usbhid: fix "always poll" quirk

Even though the IO for devices with "always poll" quirk is already running,
we still need to set HID_OPENED bit in usbhid->iofl so the interrupt
handler does not ignore the data coming from the device.

Reported-by: Olof Johansson <olof@lixom.net>
Tested-by: Olof Johansson <olof@lixom.net>
Fixes: e399396a ("HID: usbhid: remove custom locking from usbhid_open...")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>