We removed sysinstall(8) back in 2011, so this workaround should be long
since unnecessary. This workaround can end up breaking cases that are
hit in the real world, such as dd'ing a small pre-built disk image to a
large partition that you intend to grow on first boot and uses a UFS
disk label for / in its /etc/fstab (as the only reliable thing a raw UFS
image can reference).
Reviewed by: imp, mckusick
Differential Revision: https://reviews.freebsd.org/D30825
af433832f7