v2, only change is in 2/2 where a left-over __read_mostly annotation was removed. v1 cover letter: There is little to no technical reason to have an extra kconfig knob for this; nf_tables main use case it levaraging set infrastructure for decisions/packet classification. Also there were number of bug reports that turned out to be caused by builds with nftables enabled and sets disabled. This removes the set kconfig knob and places set infra in the nf_tables core.
