9p: Don't use binary sysctl numbers.

The recent 9p commit: bd238fb4

 that
supposedly only moved files also introduced a new 9p sysctl interface
that did not properly register it's sysctl binary numbers.

And since it was only for debugging clearly did not need a binary fast
path in any case.  So this patch just remove the binary numbers.

See Documentation/sysctl/ctl_unnumbered.txt for more details.

While I was at it I cleaned up the sysctl initializers a little as
well so there is less to read.

Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>