staging: wlan-ng: fix SPDX comment style in headers

Several of the wlan-ng header files had C++-style SPDX comments. Fixed
checkpatch warnings by replacing with C-style comments, as per the
kernel docs.
Signed-off-by: Tim Collier <osdevtc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wlan-ng/hfa384x.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /* hfa384x.h
  *
  * Defines the constants and data structures for the hfa384x

drivers/staging/wlan-ng/p80211conv.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /* p80211conv.h
  *
  * Ether/802.11 conversions and packet buffer routines

drivers/staging/wlan-ng/p80211hdr.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /* p80211hdr.h
  *
  * Macros, types, and functions for handling 802.11 MAC headers

drivers/staging/wlan-ng/p80211ioctl.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /* p80211ioctl.h
  *
  * Declares constants and types for the p80211 ioctls

drivers/staging/wlan-ng/p80211metadef.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /* This file is GENERATED AUTOMATICALLY.  DO NOT EDIT OR MODIFY.
  * --------------------------------------------------------------------
  *

drivers/staging/wlan-ng/p80211metastruct.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /* This file is GENERATED AUTOMATICALLY.  DO NOT EDIT OR MODIFY.
 * --------------------------------------------------------------------
 *

drivers/staging/wlan-ng/p80211mgmt.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /* p80211mgmt.h
  *
  * Macros, types, and functions to handle 802.11 mgmt frames

drivers/staging/wlan-ng/p80211msg.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /* p80211msg.h
  *
  * Macros, constants, types, and funcs for req and ind messages

drivers/staging/wlan-ng/p80211netdev.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /* p80211netdev.h
  *
  * WLAN net device structure and functions

drivers/staging/wlan-ng/p80211req.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /* p80211req.h
  *
  * Request handling functions

drivers/staging/wlan-ng/p80211types.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /*
  * p80211types.h
  *

drivers/staging/wlan-ng/prism2mgmt.h

-// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
 /* prism2mgmt.h
  *
  * Declares the mgmt command handler functions