netfilter: don't use INIT_RCU_HEAD()

call_rcu() will unconditionally reinitialize RCU head anyway.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --cc net/netfilter/nf_conntrack_expect.c
Simple merge

diff --cc net/netfilter/nf_conntrack_extend.c
Simple merge

diff --cc net/netfilter/nfnetlink_queue.c
Simple merge