Like upgrade, use feed_random right after mounting filesystems. This

Like upgrade, use feed_random right after mounting filesystems.  This
is less than ideal.  We hope the kernel has good entropy already, because
this is a reinstall??  Or maybe the ftp server startup has run to completion?
Or if this is an autoinstall, that config has enough unique in it?  This
needs more work, but the existing late-entropy feed sequence is worse.
discussed at length with rpe, who tested it