net: hns3: add build check in hclge_get_vf_isolate_bitmap

driver inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6W94W


CVE: NA

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This patch adds a build check to guarantee enum value and avoid future
issues.

Signed-off-by: Jie Wang <wangjie125@huawei.com>
Signed-off-by: Jiantao Xiao <xiaojiantao1@h-partners.com>