Re: changing ffs mount between rw and ro while preserving softdep

[Miod Vallat]

> Why not keep the softdep flag when updating rw->ro?
> E.g. via mount -ur /usr/obj
> fstab(5) already allows ro+softdep.

Because if we were to apply this diff, there would be no way to switch
from rw+softdep to rw.