HID: core: cleanup .claimed field on disconnect

When a subdriver is rmmod-ed then re-insmod-ed, the hid device is not
destroyed as it is owned by the transport layer.
So when we re-probed the device, the hid device is assumed to be already
claimed, and can lead to page faults if hid-core tries to forward the
emitted data to the to-be-created claimed node.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>