tcp: rstreason: fully support in tcp_rcv_state_process()

Like the previous patch does in this series, finish the conversion map is
enough to let rstreason mechanism work in this function.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
Link: https://lore.kernel.org/r/20240510122502.27850-4-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>