ipv6: remove useless assignment to newinet in tcp_v6_syn_recv_sock()

ipv6: remove useless assignment to newinet in tcp_v6_syn_recv_sock()

The newinet value is initialized with inet_sk() in a block code to
handle sockets for the ETH_P_IP protocol. Along this code path,
newinet is never read. Thus, assignment to newinet is needless and
can be removed.

Signed-off-by: Nghia Le <nghialm78@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20211104143740.32446-1-nghialm78@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>