selftests/net: udpgso_bench_rx: fix port argument

stable inclusion
from stable-5.10.80
commit ee79560cb768ef56d91452868d01888e97373ccb
bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ee79560cb768ef56d91452868d01888e97373ccb



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[ Upstream commit d336509c ]

The below commit added optional support for passing a bind address.
It configures the sockaddr bind arguments before parsing options and
reconfigures on options -b and -4.

This broke support for passing port (-p) on its own.

Configure sockaddr after parsing all arguments.

Fixes: 3327a9c4 ("selftests: add functionals test for UDP GRO")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Reviewed-by: Weilong Chen <chenweilong@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>

Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>