mm/kmemleak: disable KASAN instrumentation in kmemleak

Kmemleak ia a memory leak checker.  KASAN is also a memory checker but it
focuses more on finding out-of-bounds and use-after-free bugs.  Since
kmemleak is inherently slow especially on systems with large number of
CPUs, adding KASAN instrumentation will make it slower even more.  As
kmemleak is not for production use, the utility of enabling KASAN there is
questionable.

This patch disables KASAN instrumentation for configurations that enable
both of them to slightly reduce performance overhead.

Link: https://lkml.kernel.org/r/20240307190548.963626-3-longman@redhat.com


Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>