maccess: update the top of file comment

This file now also contains several helpers for accessing user memory.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-6-hch@lst.deSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/maccess.c

 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Access kernel memory without faulting.
+ * Access kernel or user memory without faulting.
  */
 #include <linux/export.h>
 #include <linux/mm.h>