Staging: comedi: comedi_pci.h: fixed missing or malformed SPDX-License-Identifier

Fixed SPDX-License-Identifier comment on first line

Signed-off-by: ankit patel <ankit.mayurbhai.patel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>