Fix broken ownership of /proc/sys/ files

D'oh...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-and-tested-by: Peter Palfrader <peter@palfrader.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>