Bluetooth: hidp: fix information leak to userland

Structure hidp_conninfo is copied to userland with version, product,
vendor and name fields unitialized if both session->input and session->hid
are NULL.  It leads to leaking of contents of kernel stack memory.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>