Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.
If bpf_map_update_elem() failed, main() should return a negative error.
Fixes: 832622e6bd18 ("xdp: sample program for new bpf_redirect helper") Signed-off-by: Wang Hai <wanghai38@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210616042534.315097-1-wanghai38@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org>