USB: gadget: udc: fix kernel-doc syntax in file headers

The opening comment mark '/**' is used for highlighting the beginning of
kernel-doc comments.
The header for drivers/usb/gadget/udc/trace files follows this syntax, but
the content inside does not comply with kernel-doc.

This line was probably not meant for kernel-doc parsing, but is parsed
due to the presence of kernel-doc like comment syntax(i.e, '/**'), which
causes unexpected warning from kernel-doc.
For e.g., running scripts/kernel-doc -none drivers/usb/gadget/udc/trace.h
emits:
warning: expecting prototype for udc.c(). Prototype was for TRACE_SYSTEM() instead

Provide a simple fix by replacing this occurrence with general comment
format, i.e. '/*', to prevent kernel-doc from parsing it.
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210522115227.9977-1-yashsri421@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/trace.c

 // SPDX-License-Identifier: GPL-2.0
-/**
+/*
  * trace.c - USB Gadget Framework Trace Support
  *
  * Copyright (C) 2016 Intel Corporation

drivers/usb/gadget/udc/trace.h

 // SPDX-License-Identifier: GPL-2.0
-/**
+/*
  * udc.c - Core UDC Framework
  *
  * Copyright (C) 2016 Intel Corporation