The sysctl knob 'vm.pmap.pv_entry_max' becomes a loader tunable since
7ff48af7040f (Allow a specific setting for pv entries) but with a
different system environment 'vm.pmap.pv_entries'. That is inconsistent
and obscure.
This revert 36e1b9702e21 (Correct the tunable name in the message).
PR: 231577
MFC after: 1 week