selftests/bpf: Drop settimeo in do_test

settimeo is invoked in start_server() and in connect_fd_to_fd() already,
no need to invoke settimeo(lfd, 0) and settimeo(fd, 0) in do_test()
anymore. This patch drops them.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/dbc3613bee3b1c78f95ac9ff468bf47c92f106ea.1711447102.git.tanggeliang@kylinos.cn


Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>