Revert r285018 and r285019, which attempted to resolve
UFS/MSDOSFS label issues on FreeBSD/arm builds, however
the real problem was addressed in r285076, which is due
to two separate issues, unrelated to md(4) stale device
existence.

MFC after: 3 days
X-MFC-With: r285076
X-MFC-Before: 10.2-BETA1
Sponsored by: The FreeBSD Foundation