usb: common: debug: Demote comment blocks which are obviously not kerneldoc

File headers and simple comments are not kerneldoc worthy.

Fixes the following W=1 warnings:

 drivers/usb/common/debug.c:15: warning: Function parameter or member 'bRequestType' not described in 'usb_decode_get_status'
 drivers/usb/common/debug.c:15: warning: Function parameter or member 'wIndex' not described in 'usb_decode_get_status'
 drivers/usb/common/debug.c:15: warning: Function parameter or member 'wLength' not described in 'usb_decode_get_status'
 drivers/usb/common/debug.c:15: warning: Function parameter or member 'str' not described in 'usb_decode_get_status'
 drivers/usb/common/debug.c:15: warning: Function parameter or member 'size' not described in 'usb_decode_get_status'
 drivers/usb/common/debug.c:216: warning: Function parameter or member 'str' not described in 'usb_decode_ctrl'
 drivers/usb/common/debug.c:216: warning: Function parameter or member 'size' not described in 'usb_decode_ctrl'
 drivers/usb/common/debug.c:216: warning: Function parameter or member 'bRequestType' not described in 'usb_decode_ctrl'
 drivers/usb/common/debug.c:216: warning: Function parameter or member 'bRequest' not described in 'usb_decode_ctrl'
 drivers/usb/common/debug.c:216: warning: Function parameter or member 'wValue' not described in 'usb_decode_ctrl'
 drivers/usb/common/debug.c:216: warning: Function parameter or member 'wIndex' not described in 'usb_decode_ctrl'
 drivers/usb/common/debug.c:216: warning: Function parameter or member 'wLength' not described in 'usb_decode_ctrl'

Cc: Pawel Laszczak <pawell@cadence.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200702144625.2533530-4-lee.jones@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/common/debug.c

 // SPDX-License-Identifier: GPL-2.0
-/**
+/*
  * Common USB debugging functions
  *
  * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
@@ -207,7 +207,7 @@ static void usb_decode_set_isoch_delay(__u8 wValue, char *str, size_t size)
 	snprintf(str, size, "Set Isochronous Delay(Delay = %d ns)", wValue);
 }
 
-/**
+/*
  * usb_decode_ctrl - returns a string representation of ctrl request
  */
 const char *usb_decode_ctrl(char *str, size_t size, __u8 bRequestType,