mempool: use new mempool KASAN hooks

Update the mempool code to use the new mempool KASAN hooks.

Rely on the return value of kasan_mempool_poison_object and
kasan_mempool_poison_pages to prevent double-free and invalid-free bugs.

Link: https://lkml.kernel.org/r/d36fc4a6865bdbd297cadb46b67641d436849f4c.1703024586.git.andreyknvl@google.com


Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>