Exporting world writable sysfs/debugfs files is usually a bad thing.  Warn
about it.
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>