Some idiot (OK, it was me) broke free_area_init_node for
non discontigmem systems that call it directly (eg sparc64),
during a recent cleanup, thus invoking the wrath of DaveM.

I know Dave sent you a patch yesterday, but I think the BUG
statement in it will break anyone who just uses free_area_init
(eg any PC). So here's a portion of Dave's patch that should
fix things for everyone I think. Unfortunately my non-NUMA
test box is borked right now, but it just removes the BUG
statement from what he tested, and it's so simple that even
I couldn't screw this up (famous last words).

This code really needs some more cleanup work, but this will
fix it for now so everyone can do their work ...