Make NET_NS available underneath the generic Namespaces config option
since all of the other namespace options are there.
Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>