selftests: packetdrill: correct the expected timing in tcp_rcv_big_endseq

selftests: packetdrill: correct the expected timing in tcp_rcv_big_endseq

Commit f5fda1a86884 ("selftests/net: packetdrill: add tcp_rcv_big_endseq.pkt")
added this test recently, but it's failing with:

  # tcp_rcv_big_endseq.pkt:41: error handling packet: timing error: expected outbound packet at 1.230105 sec but happened at 1.190101 sec; tolerance 0.005046 sec
  # script packet:  1.230105 . 1:1(0) ack 54001 win 0
  # actual packet:  1.190101 . 1:1(0) ack 54001 win 0

It's unclear why the test expects the ack to be delayed.
Correct it.

Link: https://patch.msgid.link/20250715142849.959444-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>