sysctl: Make the directories have nlink == 1

I goofed when I made sysctl directories have nlink == 0.
nlink == 0 means the directory has been deleted.
nlink == 1 meands a directory does not count subdirectories.

Use the default nlink == 1 for sysctl directories.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>