sw test tool: fix missing to receive error of PacketOut

Since transaction ID of PacketOut message is not hold,
 an error message to this PacketOut is not able to be received.
This patch fixes it.

Signed-off-by: WATANABE Fumitaka <watanabe.fumitaka1@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>