help nodes in reload_pending get sucked into reloading faster. If it
doesn't do enough, we'll need to do more batching of stuff, so we get some
parallelism in os_load instead of forcing it to serialize by calling
os_load one node at a time.

I was tempted to nuke all the stuff that was in there from the netdisk
reload type, but decided not to. It won't be too long (relatively
speaking) before we have freed, the new "free node manager" that will
replace/supersede our current reload_daemon anyway.