UPSTREAM: kasan: add __must_check annotations to kasan hooks

(Upstream commit 66afc7f1e07a1db74453be9167ac0d1205653854).

This patch adds __must_check annotations to kasan hooks that return a
pointer to make sure that a tagged pointer always gets propagated.

Link: http://lkml.kernel.org/r/03b269c5e453945f724bfca3159d4e1333a8fb1c.1544099024.git.andreyknvl@google.com


Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Suggested-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I758f33506b67ed5d4b7539745db311ab31c37f46