"dummy" switch priorities, and the users are left with no usable
/dev/random. The fix assigns priories to these and gives the users
what they want. The override tuneable has a stupid name (blame me!)
and this fixes it to be something that 'sysctl kern.random' emits
and is the right thing to set.
Approved by: re (gjb)
Approved by: secteam (cperciva)