USB: Storage: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in
header files related to USB Storage driver configuration.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used).

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Link: https://lore.kernel.org/r/20200419131653.GA6611@nishadSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/storage/debug.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Driver for USB Mass Storage compliant devices
  * Debugging Functions Header File

drivers/usb/storage/initializers.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Header file for Special Initializers for certain USB Mass Storage devices
  *

drivers/usb/storage/protocol.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Driver for USB Mass Storage compliant devices
  * Protocol Functions Header File

drivers/usb/storage/scsiglue.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Driver for USB Mass Storage compliant devices
  * SCSI Connecting Glue Header File

drivers/usb/storage/transport.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Driver for USB Mass Storage compliant devices
  * Transport Functions Header File

drivers/usb/storage/unusual_alauda.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Unusual Devices File for the Alauda-based card readers
  */

drivers/usb/storage/unusual_cypress.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Unusual Devices File for devices based on the Cypress USB/ATA bridge
  *	with support for ATACB

drivers/usb/storage/unusual_datafab.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Unusual Devices File for the Datafab USB Compact Flash reader
  */

drivers/usb/storage/unusual_devs.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Driver for USB Mass Storage compliant devices
  * Unusual Devices File

drivers/usb/storage/unusual_ene_ub6250.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 #if defined(CONFIG_USB_STORAGE_ENE_UB6250) || \
 		defined(CONFIG_USB_STORAGE_ENE_UB6250_MODULE)
 

drivers/usb/storage/unusual_freecom.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Unusual Devices File for the Freecom USB/IDE adaptor
  */

drivers/usb/storage/unusual_isd200.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Unusual Devices File for In-System Design, Inc. ISD200 ASIC
  */

drivers/usb/storage/unusual_jumpshot.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Unusual Devices File for the Lexar "Jumpshot" Compact Flash reader
  */

drivers/usb/storage/unusual_karma.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Unusual Devices File for the Rio Karma
  */

drivers/usb/storage/unusual_onetouch.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Unusual Devices File for the Maxtor OneTouch USB hard drive's button
  */

drivers/usb/storage/unusual_realtek.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Driver for Realtek RTS51xx USB card reader
  *

drivers/usb/storage/unusual_sddr09.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Unusual Devices File for SanDisk SDDR-09 SmartMedia reader
  */

drivers/usb/storage/unusual_sddr55.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Unusual Devices File for SanDisk SDDR-55 SmartMedia reader
  */

drivers/usb/storage/unusual_uas.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Driver for USB Attached SCSI devices - Unusual Devices File
  *

drivers/usb/storage/unusual_usbat.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Unusual Devices File for SCM Microsystems (a.k.a. Shuttle) USB-ATAPI cable
  */

drivers/usb/storage/usb.h

-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Driver for USB Mass Storage compliant devices
  * Main Header File