net: don't use INIT_RCU_HEAD

call_rcu() will unconditionally rewrite RCU head anyway.
Applies to
	struct neigh_parms
	struct neigh_table
	struct net
	struct cipso_v4_doi
	struct in_ifaddr
	struct in_device
	rt->u.dst

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/core/neighbour.c
Simple merge

diff --cc net/core/net_namespace.c
Simple merge

diff --cc net/ipv4/cipso_ipv4.c
Simple merge

diff --cc net/ipv4/devinet.c
Simple merge

diff --cc net/ipv4/route.c
Simple merge