kmemleak: Add kmemleak_alloc callback from alloc_large_system_hash

The alloc_large_system_hash function is called from various places in
the kernel and it contains pointers to other allocated structures. It
therefore needs to be traced by kmemleak.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --cc mm/page_alloc.c
Simple merge