inet: add TCP_NEW_SYN_RECV state
TCP_SYN_RECV state is currently used by fast open sockets.
Initial TCP requests (the pseudo sockets created when a SYN is received)
are not yet associated to a state. They are attached to their parent,
and the parent is in TCP_LISTEN state.
This commit adds TCP_NEW_SYN_RECV state, so that we can convert
TCP stack to a different schem gradually.
This state is not exported to user space.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>