kobject: Remove unused functions

kobj_ns_initial() and kobj_ns_netlink() were adde din 2010 by
commit bc451f20 ("kobj: Add basic infrastructure for dealing with
namespaces.")
but have remained unused.

Remove them.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://lore.kernel.org/r/20250112144907.270272-1-linux@treblig.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>