selftests/net: udpgso_bench_tx: fix dst ip argument

stable inclusion
from stable-v5.10.90
commit 610af55f9fbead4bd3d5636fa048d1e981a4a90f
bugzilla: 186168 https://gitee.com/openeuler/kernel/issues/I4SHY1

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=610af55f9fbead4bd3d5636fa048d1e981a4a90f



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[ Upstream commit 9c1952ae ]

udpgso_bench_tx call setup_sockaddr() for dest address before
parsing all arguments, if we specify "-p ${dst_port}" after "-D ${dst_ip}",
then ${dst_port} will be ignored, and using default cfg_port 8000.

This will cause test case "multiple GRO socks" failed in udpgro.sh.

Setup sockaddr after parsing all arguments.

Fixes: 3a687bef ("selftests: udp gso benchmark")
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/ff620d9f-5b52-06ab-5286-44b945453002@163.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>