vfio/migration: adapts to element naming changes in the vf_state structure

driver inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I773SD


CVE: NA

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the definition of the vf_state structure is changed in the header file.

Signed-off-by: JiangShui Yang <yangjiangshui@h-partners.com>