Automatic merge from submit-queue (batch tested with PRs 56337, 56546, 56550, 56633, 56635). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

should check the return value of os.DiskIsAttached

This fix is for  issue: https://github.com/kubernetes/kubernetes/issues/56455