selftests/net: packetdrill: unflake tcp_user_timeout_user-timeout-probe.pkt

This test fails the first time I am running it after a fresh virtme-ng boot.

tcp_user_timeout_user-timeout-probe.pkt:33: runtime error in write call: Expected result -1 but got 24 with errno 2 (No such file or directory)

Tweaks the timings a bit, to reduce flakiness.

Signed-off-by: Eric Dumazet <[e-mail]>
Cc: Soham Chakradeo <[e-mail]>
Cc: Willem de Bruijn <[e-mail]>
Reviewed-by: Kuniyuki Iwashima <[e-mail]>
Tested-by: Jamal Hadi Salim <[e-mail]>
Acked-by: Jamal Hadi Salim <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

tools/testing/selftests/net/packetdrill/tcp_user_timeout_user-timeout-probe.pkt

···
 
 // install a qdisc dropping all packets
    +0 `tc qdisc delete dev tun0 root 2>/dev/null ; tc qdisc add dev tun0 root pfifo limit 0`
+
    +0 write(4, ..., 24) = 24
    // When qdisc is congested we retry every 500ms
    // (TCP_RESOURCE_PROBE_INTERVAL) and therefore
    // we retry 6 times before hitting 3s timeout.
    // First verify that the connection is alive:
-+3.250 write(4, ..., 24) = 24
++3 write(4, ..., 24) = 24
+
    // Now verify that shortly after that the socket is dead:
- +.100 write(4, ..., 24) = -1 ETIMEDOUT (Connection timed out)
++1 write(4, ..., 24) = -1 ETIMEDOUT (Connection timed out)
 
    +0 %{ assert tcpi_probes == 6, tcpi_probes; \
          assert tcpi_backoff == 0, tcpi_backoff }%