Staging: comedi: comedilib.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>

drivers/staging/comedi/comedilib.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * comedilib.h
  * Header file for kcomedilib