No 4.15 final release today

As might have been expected from watching the commit stream, the 4.15kernel is not ready for release, so we'll get 4.15-rc9 instead.Linus said: "I really really wanted to just release 4.15 today, but things haven'tcalmed down enough for me to feel comfy about it, and Davem tells mehe still has some networking fixes pending. Laura Abbott found andfixed a very subtle boot bug introduced this development cycle onlyyesterday, and it just didn't feel right to say that we're done."