Allow vg exist while disk missing when check disk
Allow vg exist while disk missing when check disk

In some cases, customers' multipathes device only work when deploying,
it changes to single path disk after while.
This patch allowes check disk pass when this situation happens.

[BugFix: ZSTACK-25118]

zstackio/zstack-utility,zstackio/zstack-utility,zstackio/zstack-utility,zstackorg/zstack-utility,zstackorg/zstack-utility,zstackorg/zstack-utility