Comment 2 for bug 1287436

I initially thought that this was due to the LVM metadata parsing improvements in 2.02~beta2, but upon inspection the low-level tools were producing the same results in both 2.00 and 2.02~beta2. In fact this bug was introduced by 55e706c918922def17f5012c23cfe88c4c645208, which caused /etc/grub.d/30_os-prober to fail if --target=fs_uuid fails. I'll make it tolerate this instead, which is closer to what it did before.